Rosalina can do something similar where during hitstun she can attack with Luma. Won't be surprised if moves like G&Ws UP-B, MK's, ect. all escape.
To add to this, I was on For Glory and noticed DHD can apparently do similar with that can of his. I'm not entirely sure if he was in hitstun at the time, but it seemed like it. Might be worth looking into.
EDIT: So I decided to test some stuff out with @
Dabuz
about this actually. Here's what we got (we primarily used the same set up as used in the Rush Canceling video, Mario Down Throw>Utilt)
-Pac Man can summon his trampoline, but not his fire hydrant. It doesn't really get him out of a combo though, but it's a safety net
-Sonic can make his spring, however the spring gets canceled out and he gets hit anyway
-Duck Hunt Dog can shoot at both his can and frisbee while in hitstun. Additionally, in the above set up he can actually summon the can out and interrupt the combo with the explosion, however it hurts him and the opponent in that case
-DDD can get a gordo out...however this is completely worthless, and in fact, dangerous to you, as the Gordo will just be hit into DDD.
-Diddy cannot get his Banana's out
Pretty much it seems that any move that "summons" a seperate entity apart from the character will come out in these situations. However, how fast these work matters a lot. For example, while fundamentally the same, Sonic and Mega Man's springs produce different results. Sonic starts summoning his spring, but gets hit out of it in this scenario, while Mega Man of course just flies off without a care in the world.
Also, just because some work in some cases doesn't mean it will in others. For example, while DHD can combo break in that scenario with his Neutral B, he can't for example escape a multi hitting move like Mega Man's dash attack (where as Mega Man can escape both with his Up B). If anyone else can think of further things to test or can retest some of this stuff in a lag free environment, that would be much appreciated though.