The business can be sued if they let men in the women’s room and the real women are upset
If I had a business, I word have two bathrooms marked “family bathroom”. In it I would have one stall and one urinal and it would have a lock on the main entrance door. So if I took my grand-daughter to the bathroom, I would lock the door, she could do her thing, and then we would have privacy and no threat of someone trans-gendered barging in a woman’s bathroom.
As it should be.
Florida requires a restroom where meals are served.
I expect we'll see "private" restrooms with a locked door. I don't know what Florida will do about Interstate tourist facilities at Florida's borders with the other states. For the trans-gendered, I'd install a couple of "Porta-Johns" outside the facility.