Yes, DACUS is.. that.
Yes, every single character can do a DACUS. But for some characters, it doesn't really do anything - it actually makes a character do worse in some cases, like with Captain Falcon(what'd you expect with a bottom tier-er..). All characters have different timings with a DACUS as well, some characters can even perform it at different intervals for the same dash attack. All I know is Falco can, I don't know what the first once does though, or who else can as well.
For example, with Snake, you can't do the U-smash canceling immediatly, you need to wait a very short amount of time(yes I know, it's obvious). While with Sheik, you need to do it immediatly, considering how fast her Dash attack comes out.