Any and every action the GM doesn't like, regardless of reason, can and will get a "no". Doesn't matter what the action is. That was core to the discussion we had about my (constructed) example of the faux-Egypt paladin character being completely incapable of even TRYING to convince the Priesthood of Set to help with preventing an invasion of faux-Egypt. The GM can, in fact, reject a player's action for any reason or no reason at all. The player just has to trust that it will make sense. Potentially for months before any answers whatsoever will be forthcoming.