If Bonanno pulled it all off at once, like the end of The Godfather, I say the other families go along with it and he becomes the actual boss of bosses, or at least the major influence on the Commission. As long as he doesn't mess with the Genoveses, I don't see them really caring enough to do anything.

However, such a high profile move would mean major law enforcement attention and he would probably be put in prison soon enough. It would also mean more law enforcement attention on Cosa Nostra as a whole, so probably a dismantling of the whole thing earlier on than what actually happened.