Except we're limited by player limits, and in order to reach "MMO" status, you need to have a massive amount of players on one server. While 'massive' is a subjective number, it's common to have around 100 players on many FPS games. I would say for something to be MMO, it needs to be a server suitable for over 500 players. Almost all MMOs can hold at least 1000 players on a single server and that itself is the definition of MMO.
So please, get rid of the MMO part, unless you plan on 'emulating' MMO by having 10 different servers linked together via AIPlayers in order to cut down on the massive amount of GameConnections on a single memory limited server.
Good loving luck.