If he beats Hunt, guaranteed he will come back again. It feeds his ego and the UFC is paying him huge money. Love or hate him, he is a huge draw.
If he loses he won't be back again. However, win or lose the chances of him becoming champ again unless he fights some scrub because all the top guys are injured is pretty much as close to zero as possible.
Hunt is the best credible opponent the UFC could put in front of him in terms of chances of winning. Hunt has no sub skills and with Brock on top will not scramble out.