I bet there is nothing coming. It's all just reuse of what's already there. These people at Bungies just have no imagination what's possible with modern computers and a connected public. All they have done is a Diablo clone where people run into and out of rooms that are temporary connected. The fireteam construct is only necessary to guaranty that 3 people don't get ported to different instances of a room and some rooms have to be closed up for the public because of strikes. It's a rather simple concept of distributed computation.