I hear it's returned.
How will it affect the current engine?
In the 2D world it was used extensively with the spin jumping of all characters. In MKDA this was not present.
Therefore, will the same type of jumping also return?
If yes, I'd say the gameplay will be dramatically different.
If no, I'd say uppercutting could still have a big effect but maybe not AS much.
Still, combine uppercutting with combo breakers, some new unseen styles, some changed special moves, some changed combos and I think the gameplay will differ greatly from MKDA, although the overall engine will have general similarities (eg 3 styles).
Other thoughts?