I don't think it'll happen. Not because he is not a better fullback than Tedesco, but because he's already proven that he can be a second fullback from the centres (something which Teddy couldn't do).
So yeah, Tom a superior player but versatility means that while ever Tedesco is around, Tom will be used elsewhere. It's kinda ironic because the best chance he had for taking the 1 spot was playing poorly at centre...then maybe the thinking would be 'we gotta get this freak into the game and he is outpointing Teddy, lets pick him at 1'. Alas, he was so good, they see no reason to move him to the back because they get the best of both worlds.