I’ll make this simple. When you send your kids to public school, you abdicate all authority over them. That was always the goal and design. It is that way by definition.
I tried saying that to my ultra conservative brother in law when they stopped homeschooling and enrolled their kids in public school. He got irritated and said not his kids. Absolutely wouldn’t believe me because the constitution does not give the schools that power. All I could say is good luck with that.
By the time parents find out what disagreeable thing has been done to/with their children it’s too late for anything but complaining-the damage has already been done.