Quick reply: For some reason I had actually thought that the factions would be revealed upon death.
Not revealing makes it much more unlikely, but I'd still think about what to do in case the game ends up with two factions with the same number of players and no snipers, if only to not have possible problems. Having the first to vote win is not exactly a rule I'd personally like. Having both teams win would be the simplest, I think. It'd also mean that if a single player is left in a faction then he'd still have a winning chance, even without being a sniper.