I wish I could say "give us something a bit different" but we all know it'll have mitigation abilities that are 20% and 30%, some party heal/mitigation buff, an ability you pop that lets you use your "big damage ability" X number of times, a gap closer with a few charges, etc etc. I'm looking forward to not having to change my tank hotbar template for a possible 5th tank.

If SE sticks with what they've done previously, we'll see a tank job that already exists in the FF lore/universe. So, I don't know if the OP's idea will come to fruition.