mw13: You are ignoring an entire Sugya about what constitutes Sh’eilas Shalom. Most of the Poskim (maybe even all nowadays) hold that M’ikar Hadin it’s Muttar to say hello to someone in a bathroom because that’s not called Sh’eilas Shalom (yes, I know the M”B has a Midas Chassidus for men to never talk in a bathroom at all).
Naftush: I won’t discuss the Rama at length because people here would call me a Sheigetz for it (I know, it’s only a Rama, right?), but yes, that’s exactly what I’m saying he says. It contains a Kula, certainly. But there is a Chumra that comes along with it (although to be fair, the Mechaber would probably agree to this Chumra as well).