I am suspecting that the game will have a much smaller roster the more I hear about this "Style" rumor - the mechanic they were trying to introduce that wasn't working that caused the delay. In this case, you should expect every character then to fill in for two characters, sort of like a dark and light style they can swap between.
The simplest example for this would be Siegfried being able to play as Siegfried or Nightmare between rounds or even in mid combat. How the mechanic was supposed to work is up in the air, but I think we are going to see a more in depth version of the MK X system.
I would not be surprised of some weird new character taking the place of Mitsurugi and Yoshimitsu as one while others like Ivy and voldo return but with an alternate weird new style. If I am on to something, I would also expect alpha and Omega variations to return but under one character. If this is true, I'd expect patrok and pyrrah to return with more.refined styles, and setsuka, Sophie, and cassie gone still.
Eg Astaroth and Rock would be another merge in styles.for example. The list goes on.