I just can't see THM being moved to "White Mage".
Why would they give CON the Curaga and Raise line of spells if they were intended to be given to THM's job? Sounds kind of silly to me.
It makes more sense for CON to move to White Mage at this point in time due to the last updates CON received.
That's not to say that THM will go to Black Mage. You still have Dark Knight or Time Mage, or various other things a THM could move in to.