Noticed this too.
I've also noticed a problem that sometimes happens with Ganon's side-b. If used in the air and it hits somebody, occassionally, the opponent ends up behind Ganon. I never had this happen to me in vBrawl but I didn't play all that much with him then.
Aaaaand sometimes, while using a recovery move with straight horizontal movement on the main platform of the Delfino Island stage, such as Fox's side-b, they will completely go through the edge and fall to their death. Also not sure if this was in vBrawl, but it kinda sucks.