Whether Shawn Michaels turns heel or not is irrelevant, he should not be attacking Bret Hart. Hart and Michaels reopening their feud will lead to people questioning why Hart hasn't got his revenge on Michaels, and it will reopen the closure that has already come to this feud. It would only serve to make people think that there would be some future confrontation there, which there wouldn't be. Basically, it is unecessary and it would be distracting. If Michaels turns heel, then that's that, but it should be at the expense of whoever he faces, and it shouldn't open up an irrelevant closed door.