The reason the rumor came to be about making their debut last night is because the duo has been backstage at main roster events this week, along with Carmella.
It’s being confirmed that WWE is planning on bringing the three up together very soon and is said to be a lock because WWE creative is discussing ideas exactly how to bring them to the main roster.
Typically, WWE will wait to debut new stars from NXT like that after Wrestlemania, but the speculation is that WWE may wait until then, or they could pull the trigger earlier and set them up for Wrestlemania 32 in Dallas.
Enzo and Cass vs. The New Day is probably in the cards, and a betting man would probably have the NXT team be the ones to take the WWE Tag Team Championship off The New Day to establish them as a top face team in the division.