To be honest, I do have this head-canon of every time you beat one, you move to the next. So, I have no problem with it later being a combo AB/EX server. I do question whether that allows us to keep our levels though. If it doesn't, I am not willing to start all over again. I hate the early levels and don't consider losing all this progress to move onto maps that I actually don't like. (No, I don't like aberration or extinction, but will play if I continue my character).