One of those situations where you have to weigh your paycheck against greeting stabbed in prison.
I really don’t think that’s the issue at hand here. Reading the article you’ll see that the student in question is changing alongside the rest of the boys; if the coach were to face a false accusation there would be a class full of students to testify on his behalf.
Not only that, but a source article for the one linked, The Federalist, feels the need to bring up an unrelated accusation regarding an alleged assault of a kindergartner in a bathroom, by implication suggesting that this boy is a physical threat to the other students.
The teacher’s claim is that he doesn’t want to see a naked adolescent female body. I would have to ask first why he can’t simply look away, and if “overseeing” the students means he even has to be in line of sight of them. When I was in school, the gym teacher had no way of seeing every boy undress from his windowed office (it was, granted, a different generation).
The objections here seem as much to be concerned with the idea that the boy is causing other students “embarrassment and concern” although the lawyers who are involved don’t claim to be representing a single one of them.
It seems to me that it comes down to the fact that these coaches and their evangelical Christian legal counsel simply don’t like that their school recognizes a right for a transboy to use the boys’ facilities.