Confusing, guess we'll have to wait for details. Are we talking a MVC type of assist or what? I hope MK is not running into identity issues similar to the 3D era to where they just didn't know what to do with the series anymore.
MK9 had a tag team mode where you played 2 characters and you could call on your partner for assists to extend your combos, extend your pressure, enhance your zoning, enhance you mix ups, etc. so i guess it's based on that
although the fact that the press is refereeing to the game as "Assist based" rather than "Team based" leads me to believe that the assists will work less like Marvel 2/Marvel 3 i.e team based fighter w/ assists, and will work more like Nitroplus Blasterz/Dengenki Bunko i.e 1 on 1 fighter with assists, sounds like it could be cool, gotta wait for more info