It could have changed, as Sakurai has shown I shown things have changed mid development, but momentum is seemingly unchanged for the most part.
Looking at Sonic do a jump after that reunion is a bit unsettling, but hey, things can change. However, if there is no change after E3 then it is official.
Unless they made the jump similar to street fighter when you gain more distance with a super jump. Maybe something like holding down then hitting jump to do a jump with greater moment, kind of like how in Mario 64 when you run, crouch and jump you do a longer jump. It wouldn't be the first time they introduced Mario-esq mechanics in smash. This would also bring back crouch canceling.