I'll say this concerns me, though. Based on the sheer numbers, sooner or later something is going to go wrong. Some mean girl is going to harass a transgirl, or a garden variety male bully is going to hassle a trans guy. We'll hear from the Huckabees and the haters, "see, we told you this would happen," and the whole thing will be controversial.
A much stronger argument, one that is not dependent on the miracle of zero incidents, is to point to the overwhelming incidence of bullying of transgender students, depression, anxiety, and suicide, etc.