If there's ever a reason they want or need Chyna to come back, all will be forgotten and she'll probably even go in the HOF. At the end of the day, Vince makes the final call. If he picks up the phone it probably doesn't even matter what Steph thinks about it. After Warrior and Bruno, anybody's possible.
Benoit's probably the only one that'll absolutely never happen. I don't know if there's enough years to salvage that, there's nothing financially beneficial in it, and the heat they'd get for it would be nuclear.