Since the game franchise isn't as over as some game franchises, I think it would be a bit of a silly move to just have the next installment exclusively for next-gen consoles. However, with that being said, it'll probably just be the same old crap, with just a few minor improvements for the next-gen releases.
The WWE games have pretty much been the same old shit for the past few years. I was really looking forward to WWE 13, with the whole Attitude era thing going on, but it was the same old stuff in the end, just with a hell of a lot of glitches. I got excited for 2K14, but once the 30 Years of WrestleMania mode was complete, that was it.
I don't really know what they can do with the next game. Maybe have a full NXT roster?
I just don't want to see the developers wetting themselves over it in previews and selling it as the best fighting game of all time! [But I guess that's part of their jobs. Punks...]