I think it's way too early to say something like this.
That said, just from experience and observation:
Roy has a much more consistent and present combo game. Roy threatens shields MANY times more than Cloud, simply because Roy gets free combos and tech chases from throws at pretty much all percents. Cloud pretty much has little to no throw reward besides positioning. Keep in mind though, that having a weak throw game isn't that bad anymore; Ryu has proven in spades that even weak throw followups are not a problem if you are good in other locations.
EDIT: I think I need to add this here, but it looks like people are finding that Cloud CAN actually followup from dthrow at low percents using perfect pivot into up tilt, so I wouldn't say he CAN'T followup as that'd be inaccurate. But he still doesn't seem to be able to do much outside the first 15 or so percent.
Cloud with limit kills earlier than Roy, or anyone really. He can confirm into kills from around 60 percent upwards with no rage, or even earlier at the edge. Without limit though, Cloud is unable to confirm into a kill; he has to land one of his kill moves to do it. He's limited basically to Up air, back air, and f smash for realistic kills without limit. With limit he adds Up B, Down B and Side B to the list, which can be confirmed into from any aerial (some of them are easier than others though, many require a grounded opponent), sometimes dtilt. Roy's earliest kill confirms start around 100 or so, but an Fsmash read can more closely rival Cloud. Nair 1 into Jab into Blazer is probably Roy's earliest kill confirm in the matchup. So Cloud definitely wins here imo, even though Roy's confirms are a little easier to land.
Another advantage that Cloud has in the matchup is that he also has a disjoint. Roy tends to struggle a little more in matchups where his opponent has a disjoint(especially one longer than his), as it greatly hinders Roy's ability to pepper them safely with weak hits from outside their reach, or to be safe when approaching with nair 1 etc. That said, I'm not sure how big of a deal it will be, as Cloud's grounded reach & speed with his sword is not that impressive. For example, Marth can stuff Roy's air approaches with jab, Ike can do it with up tilt, but Cloud doesn't really have something with the diagonally up and forward speed or reach that those options have. His up tilt doesn't hit very far in front of him and his ftilt doesn't hit very high up or very quickly. So my gut instinct is telling me that Roy isn't going to have as much trouble with a Cloud on the ground as it might look like. Now, in the air I think Cloud has Roy beaten, as his forward reach and speed is just a lot better than Roy's. Nair has good range and is quite fast. Fair is slow but reaches further than Roy's options in the air.
Finally, Roy can MUCH more easily gimp Cloud than the other way around, unless Cloud has limit. Roy should have NO problem ending Cloud's stock once he's offstage without limit, much like Captain Falcon. The lack of Cloud's ability to snap to the ledge without limit is a major, major weakness of the character. You could just sit at dtilt range from the ledge and repeatedly dtilt him every time he pops up to grab the ledge, and he'll never be able to grab it. Or you can back air him into the ledge. Or you can just charge b and release as he comes up. Theoretically, if you hit him off stage and are near the ledge, he should never make it back if he has to Up B unless he has limit. I'm serious, it's about as bad as Little Mac's recovery, it's actually probably even more gimpable since the hitbox doesn't reach up as high. Though, good Cloud's will probably never use their limits except for guaranteed kills, so he may have limit more often then not. We'll just have to see how it goes.
I just realized that I typed up way more than I should have for a character that just came out lol. I'm not saying this is the matchup, but it's just my prediction. I think it will favor Roy slightly.