This isn't going to exclude trans athletes from high school sports. It's going to exclude out trans athletes from high school sports.

Which means that athletes who don't look sufficiently feminine are going to be exposed to invasive sex verification. That's apparently a requirement of the Idaho law for any athlete whose sex is disputed, though it's blessedly resulting in some clearly necessary legal issues.

Just think that through, and think about which girls are most likely to be exposed to this evil violation. If people think this duty of "protection" isn't going to be used as a way to enforce racial and heteronormative ideals of the "right" kind of girl, then I think they're being extremely naive.