I'm wondering... how would you want to decided who gets to stay on which server after the split? Who goes to BalmungA and who to BalmungB? Randomly? You get to choose one of your liking?
If you get to pick, you most likely pick the server your friends are going to, right? Like... a whole group decides to which server they're going to move... you see what I'm getting at here? If they split the server and everyone gets distrubuted randomly, theres going to be an outcry about splitting friends, FC, communties... if you get to choose (and most likely decide together with your group) - how is that going to be so different than having your group discuss moving together, now that we're having free transfer? Just because a split would actually force you to make that choice?
Splitting the server would essiantially be creating a new server - and why should they bother when there are quite a few servers on your datacenter that you can fill before they make a new one?