That would not be enforceable because there is a law (the ADA) that says they must allow those people. Until there is a law saying that private businesses must admit people without masks, those people may legally be excluded from the property.
Don't get me wrong, I loathe these mask requirements; however, I am being forced to comply.
:: Until there is a law saying that private businesses must admit people without masks ::
In the same manner that person is innocent until proven guilty, there must necessarily be a law (regulation) that businesses REQUIRE masks for accommodation.
Not the negative.
Laws that regulate a negative are not laws.
Health department regulations REQUIRE shoe sand shirts be worn in food service businesses.