Bryan will never get turned on because he's probably going to be a case like Christian where the IWC thinks he's getting fucked in the ass, month after month, year after year, and they'll stick with him on that principle. It's the same reason they haven't turned on William Regal, they only turn on people once they succeed and they can re-focus their affections towards someone else.
As for CM Punk, it depends mainly on his position and his health. If he's booked as a Jericho-esque wrestler, as he often is, that's capable of working the entire card and losing in any situation WWE feels necessary, but is still considered a main eventer and only touches the world title once every 2 or 3 years, they won't turn on him, much like they haven't turned on Jericho. If he ever becomes a permanent, major main eventer, which everyone wants, there will slowly be an outcry of how he's become stale, boring, etc. His health would also be cause as I mentioned. If the IWC feels his performance is dwindling due to a series of injuries, they'll turn on him like they did Edge.
The other scenario that would cause a turn is if Punk pulled, what I assume would be known as "The John Cena", that is to say, turning into a character that's the exact opposite of what made him popular in the first place. However, I don't think this is a danger because I don't think Punk would ever allow that to happen, that's just not who he is.
