Would LD really be worth the trouble of fixing if this is sorta like Melee 2.0. I mean street fighter keeps basically the same game and just updates graphics and combos and stuff between each game. Things like landing on your feed makes sense. Sure it's different from melee, but it's an improvement. It may make things harder or impossible perform that were in melee, but we can just count on the developers of Project M to come up with something to simulate or replace it. Players should just adapt.
Uh yes, it's definitely very worthwhile to fix. Mario's SH Bair waveland is impossible to do, Marth's SHDF is very difficult to do, SHL and Missile canceling do not occur as low to the ground as they usually can, IIRC Ganondorf can't stomp through platforms (Falcon apparently still can?), platform wavelanding requires a couple more frames of height above them to work, and of course full WDs are easier and L-canceling timing is off (which can adjusted to, of course). Landing earlier in general can make it harder to land aerials on grounded short characters (or characters laying on the ground). It's something I've always been annoyed with when using Link and his Fair and Bair.
So no, it's not technically an improvement at all except from a visual standpoint. It's not about making it like Melee just because it was like that in Melee. If it can be fixed, it will be because it will be a nearly universal improvement. In the case that a solution is never found then yes, they will find alternatives. Adapting can be applied to pretty much only one of the examples I listed. All the others are technically limiting minor, but still important factors to almost every character.
Eh, that sounded kind of ranty in my mind.