I know this might get a lot of flack because MK4-MKA weren't popular for the time and MK9-MKX have a big reputation, but I believe that NRS should take their chances and make MK11 on a 3D fighting plane.

One thing that's impressing more than the characters in MKX are the levels,
they are magnificent, however we can only see about a half of whats going on in the background because of the camera setting. Also there's more space for the players to move around and interact with the (amazing) environment if they convert to 3D.

I might have made another post on this months back, but there's not much else they can do to in terms of gameplay if they continue fighting on a 2D plane without adding long-ass string combos or adding Smash bros platforms. I don't really see anyone going crazy over MK going on a 2D plane anymore, I think its rather outdated and it adds way too many restrictions to characters play style.

Mortal Kombat was more popular during the 2D era you say? Guess what else made them more popular: arcades, media attention, movies, advertising, and all the other spin-offs that gave the classic characters more attention. This ain't the 90s no mo...maybe hardcore fans on the MKO and TRMK see that, but sadly the majority don't. So they'll probably stick with 2D...its sad really.