It looks pretty bad honestly. So the point of wavedashing in Melee, most of the time, is that it lets you move with free access to all of your standing options at a much higher speed than walking. Basically, a Melee wavedash's biggest selling point is that you get most of the benefits of walking and running at the same time, and that's pretty good. However, in Smash Ultimate you can just act freely while running which is faster than wavedashing and thus supersedes the functionality. However, it's even worse. In Melee wavedashing is indeed totally uncommitted just like a walk, but you have 18 frames of lag every time you start up a wavedash in Ultimate which is going to be a large percentage of the movement time. Yeah, that's horrible. For general utility, that's useless.
There may be niche utility though. For one, not all characters are created equal, and some that don't run the quickest and have very low traction might get enough movement to maybe think about it? Luigi is definitely the most obvious case, but maybe Ice Climbers too? Even for them I'm skeptical the speed is really worth it (running is just visually really fast in Ultimate; it's a lot to compete with), but it's at least worth checking out with only those most extreme characters. The other thing is that in Melee wavedash had a kinda secondary use that it would slide right off the stage and let you grab ledges much faster than other techniques. It's unclear if it still slides off-stage in Ultimate, but if it does, it could be pretty useful for ledge trump set-ups since you don't really care about lag frames on stage in those situations you just want onto the ledge ASAP and it might be the way to do it. Even if it doesn't work, then the optimal trumping set-up is probably a triangle jump anyway so something similar in concept to a wavedash will totally be a thing for that.
Disclaimer that I'm not a pirate and haven't played yet, but on paper this just seems really clear. Why would you want your goto movement option to be slower and filled with lag when you could just run?