But that wouldn't be this kind of situation. If Gunn were asked by Wright to complete his film, then, in order to honour him, Gunn would have to film it exactly as Wright wanted it and not to change his vision to what Marvel may now have changed it to. If he did go against Wright's vision, then Wright would not ask him in the first place or endorse him as director. And if he went against Marvel and went with Wright's vision, then Marvel wouldn't be asking Gunn.
So I think Gunn would be in an almost impossible situation here where whatever he does, he's screwed in some way. So it's probably best he doesn't get involved and lets Marvel pick some other director who won't feel there is a conflict of interests.