1. AFAIK - If a kid decides to change their pronoun around their friends the school is not required to report that now and would likely not even know or care. If they do no make an official request to Teachers or staff etc then who's to know. This reminds of when fundamentalist claimed prayer was banned in schools. That has never been the case. School lead or Staff lead prayer was banned. Any child that wished to pray before eating lunch was totally free to do so.
2. It assumes that knee jerk reaction on the part of all fundamentalist parents. (feels weird for an atheist to defend fundamentalist but here we are)
3. Where's the data to back this decision up?
4. There are likely situations where it might be important for the parent to know what their child is doing. What if they are in a cult and want to change their name to unintelligible gibberish - wait Musk is probably ok with that. What if someone is convincing them to get illegal surgery?