The game seems to automatically set input delay based on your connection, the worst a connection is to a person, the more input delay.
GGPO generally lets you set how much input delay you want yourself, so you can choose to have a shit ton of rollback or input delay.
Doesn't seem like MKX is going to go that route, and just adjust it on the fly during matches, which is kind of annoying.
Right now they could be just testing something and have the input delay higher then normal, IDK, I haven't played this version of the beta yet.