I don't think anyone would use that construction though in the midwest if they only meant the men. If they wanted all the guys to get off the dance floor they would say "Now, all the guys are going to step off the dance floor." "The guys" is much different than "you guys", at least where I live.
Granted, it is murky so I also don't really care about switching to y'all. The only problem I have with "y'all" is that it is such a southern thing that using it to me with my midwest accent sounds forced and awkward (At least to my ears).