People seem to be mistaking my fanboyish wet dream as something they can discourage through logic.
Anyway, Smoker is incredibly high in rank for someone his age, and Oda has stated that his rebellious attitude holds him back. So maybe his actions nab him the promotion.
Who was the last Vice-Amiral we saw apart from Garp? If we haven't seen any in a while, maybe they all died in the battle.
Garp already rejected becoming an Admiral several times, he would probably be in Sengoku's position if he pursued his career, but he never wanted to be promoted. I don't see why that would change now.
I would think that one of the Vice-Admiral get promoted and Smoker gets promoted as well into that Vice-Admiral position. I don't think Smoker is ever going to be higher than Vice-Admiral because he just want to climb ranks to pursue Luffy and he doesn't like to be ordered around.