MMO's are a little dubious in the first place. In the starting days of WoW, the idea of a whole community interacting and organizing through the game itself was very special. But in the end everyone just likes to play with a fixed group of friends and call it a day.

So if that's the case, you'd call any game that integrates gameplay and community an MMO.

And no, I don't think Jazz should go in that direction. If a new Jazz game is made, I wouldn't mind it having RPG elements but multiplayer should take a more traditional approach including a serverlist and standalone matches.