FF13 and 13-2 was ATB, just more dynamic, and with command queuing. There's no reason why a new game would have to have skill trees even if some of the most recent games had that. FF10-2 had a classic job system, and we hadn't seen that since FF5 (or FF Tactics if you want).
FF12's combat was not very MMO-like. I've played WoW, FF11 and FF14 (and a few other minor ones) and none of them feel anything like FF12.