So, in other words.. You are worried about those idiotic laws, that require people to use the restrooms according to the gender they're born with, right?
Because that's exactly the very side effect taking place if those idiotic laws are upheld.
Does not matter if you're a dude with a beard and stuff. In case you were born a female 40 years ago, off to the women's restroom with you.
Or Caytlin Jenner will be off with the guys again, where Bruce used to take a piss.
There are heaps of people that look 100% like the opposite of what they've been once.
You could take identity tests until the cows come home, and you would probably never guess the correct/original gender.