Yeah it's one of those popular jobs on the tier below blm, whm, dragoon, etc and Yoshida likes the classic jobs a lot specially when he has a chance to give it a new perspective like they did with dark knight. I bet that he's going to make Geomancer a tank. No one thought dark knight was going to be a tank and we saw what happened. A tank mage would be something new and unique, in FFXIV they might turn it into a melee mage with low range but keep the casting which is ultimately what defines a mage.