If he really did turn his life around I don't think his chances will be that slim. I watched one of my friends turn his life around and it was an amazing sight to see.
Setoguchi is only 28, if he really changed I think he will have a really good shot at making the team. His biggest problems before was his shape and his attitude, not that he lacked skill. If he really accepted his demons and did something about it, I expect he would show up to camp in great shape. And if he really is in great shape I expect him to be one of the better forwards out there. Again that is if he really changed his ways.