What a crock. If he wants to quit, he should just quit. He's probably avoiding some undisclosed blast of shit from somewhere by coming public with it. I don't buy into it for a second. And why announce it to the world? That's just dumb.
I've known lots of people who were addicted to various things who went to rehab (either voluntarily or non-voluntarily). All of them went right back to their vice/vices of choice as soon as they got out. I always found my druggie friends' "when I was in rehab" stories highly entertaining when we were sitting around doing coke.
You quit when YOU are ready to quit. Not before.