IMO it will depend on how much landing lag Corrin's Bair has.
Pretty obvious, but if the move doesn't autocancel out of a SH (and presumably has some notable landing lag) it'd be pretty dumb to do it since you'd be sliding into your opponent while in lag, which just screams "Punish me!"
The obvious benefit of any sliding mechanic is that usually the character can act out of the slide immediately, characters with good DITCIT distance such as Link (AKA Bombslide, more colloquially) benefit well because it allows for an unexpectedly fast approach option after which he can Jab, DSmash, Grab, etc. And this is more Bomslide/DITCIT specific, but because he's throwing an item he can use the item throw as a bait to force the opponent into shield for a grab (since the natural reaction is to assume the item will be thrown at you, when it can be thrown forwards, upwards, or behind Link during the slide), and this works whereas a simple dash throw wouldn't for getting a shield condition -> grab because Link moves further out of a bombslide then he does a dash throw.
But I digress.
The point is, if Kamui can't safely do anything after hitting the ground from Bair and initiating the slide because of Bair's landing lag, I can't seeing it having very much use.