Yeah I’m sure there would be a regulation against it, and you’d need to brand them as rest centers or something.
And I think public access to toilets, at least in NYC, should probably be something more like the subway system than a service just for those that can pay a lot. Even then, the subway isn’t really a life need in the way a toilet is. (Yes I’m aware that it costs money to ride the subway, but it’s not very expensive.) I can imagine the service I described being branded by the press/public as bathrooms only for the rich.
As I said, norms around this aren’t the same around the world. It’s normal to pay for a toilet in Europe but many Americans have a negative reaction to the idea.