I don’t think there should ever be threats to kids. In fact, I feel sorry for the kid.
However, I think the parents should have just said nicely that their daughter does not feel comfortable attending the school because the transgender boy is looking at the stalls, and then kept their kid home. If enough kids keep their kids home, the district will get the point.
I’m also beginning to think that there may be a time for a class action lawsuit against public schools in general for discrimination against conservative, Christian kids.