Ftilt was already sped up. Its endlag iirc, so it's already pretty damn safe.
I know, it needs to be a bit faster, it comes out too slow, there's not a single use for it, any time I think I can use it, it turns out it's too slow, or there's a better more powerful option(Fsmash, Fair, Dair, etc.) I remember Skler saying it needed to be made faster, and one of the Devs just wrote him off saying they already did, without realizing he meant it needs to be even faster.
Link's ftilt is fine now. It's actually decently fast and covers a lot of area.
I'm saying having the side-tilt faster isn't going to make Link broken, not at all, he'll still more than likely be worse than most of the characters, but it would put him up with the rest in terms of viability at the very most