Parcells doesn't run the show. The Jonese do. (Jimmy Johnson found out what happens to coaches who don't just shut up and do what they are told.)
I don't think Jerry Jones is going to for it either.
Parcells DOES have the choices of whether to play him or not. to cut him or not.
Vick probably would be a practice squad guy with the Cowboys.
That is not the case in Dallas at all. Parcells is very much in demand and can coach anywhere he wants. He coaches the Cowboys for as long as HE wants to.
It's not like Parcells is cowering to any owner saying "you're the boss - please don't fire me".