R.O.B
I don't have too extensive of experience with him, but I'll try to answer how I generally play the MU.
NEUTRAL
Zelda is fairly good at shutting down most zoners and has lots of ways around projectiles. Phantom lingers for quite a while at higher charges and lower charges can be used as quick walls to stop projectiles and allow Zelda time to set something up. Gyro can often be either reflected by Nayru at longer distances or blocked with Phantom. His laser goes through Phantom IIRC, so either reflect with Nayru or hop over it. If you have a good handle on the distance and lag of Farore's Wind, you can jump and then Up-B punish any projectile attempts. Rob's animation during them is fairly long, so he's pretty open to punishment by FW.
Rob's only real answer to Phantom is to either jump or use his reflector(that spin move). Jumping can put him at risk of being punished by Zelda. Up-air is very good and will beat most Dairs, so use that against Rob when he's above you. Rob has difficulty landing and will have to rely on Up-B trickery and Dairs to land, most of the time. Don't be confused by his stalling and punish the endlag on Dair.
Fully charged Phantom can be used to bait out his reflector and you can jump above him and punish with Dair on the blind spot(his head). Alternatively, you can wait until after the Phantom is reflected and then drop and punish with a stronger move like Fair/Bair or Up-B when he's finished spinning.
His roll is really good and he has some pretty good poking tools like D-Tilt, so be cautious up close. His grab is also good and can lead into his down throw, which will bury you, so be cautious when shielding. I think your best bet, is to fight him at a distance and try to force his reflector or an approach and then launch him in the air or off stage.
ADVANTAGE
Once you win neutral and have him in the air or off stage, you need to keep him there as long as possible. The longer you can keep him there, the easier this MU will be.
In the air, what I said above about using Up-air will suffice. Don't be tricked by his stalling, don't over commit and try make him run out of his Up-B or force him to the ledge. If he starts heading to the platform, Nair can be used to punish and dogfight in platforms. If he starts heading to the ground or air-dodges towards there, dash attack will send him off stage most of the time. For all other cases, Up-Tilt will continue juggling his attempts to land and allow you some versatility in spacing around any Dairs or his reflector mixup.
Off stage, Din's Fire is really good at sniping big bodies like his and the sweet-spot should instantly KO. Use it if he is far above the stage in the corner, or if he is below the stage near the corner. If he is a bit above or even with the ledge, Phantom is pretty good at sniping around there and will also instantly KO. Otherwise, Dair will spike his recovery fairly easily, given there's no hitbox above it, just be careful of his Up-B stalling or you might be the one getting spiked.
Depending on your timing, you can Fair/Bair his recovery, which will KO or stage spike into an untechable at high percents(not sure of the exact percent yet). You can also stage spike with Nayru, which while weak, can be used with a fully charged Phantom setup at the ledge and combo into it's slash. If you don't have time to do those, the usual Phantom ledge trapping shenanigans will work, just be on the lookout for a reflector getup.
DISADVANTAGE
Rob has a pretty good advantage state, so you need to be careful. If you're caught in the air, you need to give yourself more height by jumping, because his Up-airs are nasty and can juggle and KO really easy. He can't really chase you very high in the air, so adding more height can allow you to either get to the ledge or bait a over commitment from him, which will allow you to either Up-B to the ground or fast fall to the platform as he's landing from a failed attempt.
Off stage, Zelda is really difficult to edgeguard, so you can rest a little easy here. Other than random Gyros, which you need to be on the lookout for, or a reflector near the ledge, which you should recover high or low to avoid, his only real option is to try to 2-frame you at the ledge. Mixup your recovery with jumps and stalling and try to bait a Dair attempt. Time your recovery to coincide with the endlag of his Dair. I personally haven't played any Robs that were good at 2-frames, but that's not something you should be assuming.
Wolf
I don't think there's any magic bullet or strategy in this one. He's so basic and neutral focused, you kind of just have to outplay him in neutral.
NEUTRAL
The biggest thing is patience. Wolf thrives off of punishes and being able to pressure in disadvantage. If he camps you, camp him back. Phantom gives you options and doesn't let him camp for free. The full charge's delay, lets you bait his reflector and allow you to punish, in a similar way to Rob's. He'll have to move eventually, so feel free to charge it, if he deigns to camp.
His neutral air is one of his main neutral tools. It can be parried fairly easily, so try to do that or just shield and often times you can punish with an OoS option. If you're good with Up-Tilt, that can be spaced in a way that will combat Wolf's aerials fairly well. Nair can also work as a good preempt, if you know what and when he is going to use.
The biggest issue you're going to face, is his laser. It can shutdown Phantom charge attempts and force you to break camp. If you're quick about things, you can release Phantom and it will act as a projectile wall. You won't get much off of it, but it can prevent you from being hit when charging. Reflecting can work, but you likely won't hit long range and Wolf can get hit and still punish Nayru's copious endlag up close. It's best to just do an empty full hop fast fall while charging Phantom or learn the Phantom displacement technique. Regardless of how you go about it, this is where neutral is going to be focused on the most and there's no easy answers. All I can really say is be tricky with mixups in avoiding laser and try different spacing methods to punish/gain stage control and hopefully discourage him from using this too much.
Try not to approach him as much as possible. His F-Tilt is good for stuffing approaches and Up-Smash is good for stuffing aerials. I think this MU will be centered around who can make the other approach first and neutral will be focused entirely around that. Unfortunately, I'm not really solid on this MU, so I don't much to offer in how you go about doing that, other than what I've already mentioned. I get by and that's about it.
ADVANTAGE
Unfortunately, you're not going to get much out of advantage. Low percent strings will work, but his base attributes are too good to really pressure him. This MU is very neutral heavy and you'll likely get Up-air or Fsmash reads at most.
In the air, you're going to need to pay close attention to DI and where he likes to land. He has quite a lot of mixups with jumps and his natural speed and agility, so it's going to be difficult to land anything. If you can force him to burn his jumps and read his DI, you can use Up-air to snipe. Nair is good at preventing him from moving through the platforms. Up-Tilt is good at catching bottom platform and ground landings.
Off stage, it's surprisingly difficult to edgeguard him. His Side-B is fast and can spike, so it's dangerous to try to contest it. Instead, try to time a jump above it as he tries to hit the ledge. It generally won't snap immediately, so you can Dair spike with good timing. Phantom can also hit him, but the timing is tricky. Learn the angle he needs to snap to the ledge and if he is not at the correct angle, even after his jumps, that's when you can go off stage. His Up-B is powerful, but slow. You can use Din's Fire to snap the long startup, if he has to do it from an angle away from the ledge. Otherwise, Dair can spike it, just be careful with the timing, as that Up-B is powerful. Nayru > Phantom slash shenanigans will also work.
DISADVANTAGE
Wolf can pressure pretty hard at lower percents, but like with most other characters, Zelda can float out at higher percents. He doesn't get much from Up-air, so just try to DI around it and get to the platforms. The main things you need to be careful of, is his Bair and Up-Smash. Don't try to land with Dair or contest him in any way. Focus on making it to the platforms or the ledge. Bair has some startup, so he'll likely be looking for an air-dodge, avoid that as much as possible, unless it's into the ground.
Off stage, there's nothing Wolf can really do. Never recover high, as that's where he likes to Bair KO you at 80. Like with Rob, mix up your timings, as Dsmash is still pretty powerful, even with the nerf. If you need to, you can Up-B past the ledge and hit him when he tries to Dsmash. Din's Fire also can work to force him in shield and hopefully allow you time to quickly jump/Up-B to the ledge.
Ike
Ike's fairly linear and not as difficult of an MU as he first seems.
NEUTRAL
Ike spams a lot of aerials and waits for you to approach, because he doesn't have a lot of approach tools. The key here, is to out range him with a bigger sword(Phantom). If he's camping, start fully charging Phantom and then move up as he backs off. Use Phantom to keep as much stage control as possible, while chipping away at him. You can occasionally use Din's Fire as a mixup here, to keep him guessing. This will often force him to approach, which you can then shield/parry options like Fair, then punish OoS. Your main goal here, is to build enough damage to knock him off stage, where you can then continue punishing his recovery.
ADVANTAGE
Once you knock him in the air, Up-air is usually quick enough to hit him before his aerials have time to come out. Nair can also hit him before his Fair has time to swing down. Just watch for Bair coming off the platforms, it's insanely fast and will kill you early.
Offstage, is where the real party will begin. Phantom will stop any Side-B recoveries, that aren't done high over the stage. Din's Fire can snipe ones high over the stage with good timing. Otherwise, just be ready to intercept him when he lands, as the endlag is fairly small. You might be able to Up-B, if you know where he's going to land and don't have time to make it there.
If he's forced to Up-B, the scoop Phantom slashes hit under the ledge and will knock him away, because his Up-B doesn't snap to the ledge. It's GG once that happens. Alternatively, doing Nayru's Love behind him will knock him out of his super armor and stage spike, but that's not really a situation you're going to be in very often.
DISADVANTAGE
If he gets you above him, you need to DI out ASAP. His Up-air is insane and he can combo you for days. Make sure you DI in FRONT of him or he can combo into Bair and kill you really early. Try getting to the point, where you can jump out of it and hurry to the platform or ground, as he's often too slow to chase. Just be careful of any potential dash attack chases, that move is fast and covers a lot of area. You just need to get to the ground as fast as possible and stay there.
Off stage, there's not much he can do, other than random Fair chases or the odd Up-B B-reverse. Don't recover high and don't recover at the angle that's lets him drop off Fair. Try and make sure you have an aerial Phantom covering your recovery, as his neutral B is very good at 2-framing Zelda's recovery. If nothing else, try to Up-B past the ledge and hit him out of it.
i wish I was good at Zelda ;-;
Just sharpen your advantage to offset your disadvantage and learn to mitigate damage in your disadvantage as much as possible. Otherwise, learn and grind lots of different MUs, as MU knowledge and experience is incredibly important for Zelda, who will sometimes need to change up her style depending on the MU. Phantom in particular, needs to be used differently in different types of MUs.