One must also realize that, per Mopping for
Theatre 101, our idea of wet mopping is different than most people's idea of wet mopping. Yes, the floor must be painted or sealed all over in order to prevent damage. Even painted, proper mopping doesn't involve dumping water on the floor. It involves wetting the mop, ringing it out and giving the floor a once over that leaves it slightly damp. Anymore except on major sticky points is wasting water, finding a way to waste time and does risk damaging the floor.
Chances are you architect was also stating that to avoid liability should the floor receive water damage down the
line.