Opposed to cutting out parents
Any policies that is open to ignoring or dismissing parents runs counter to schools' mission of supporting students. Supporting discord between a student and parents harms the family and parent-child relationship. Parents should be fully informed at all times, doing otherwise infringes on the parents' First Amendment rights.
Additionally, young children should not be forced to share restrooms, locker rooms, and overnight accommodations with someone of the opposite biological sex. There is a hightened risk of trauma in those situations.
Additionally, there is risk to health and wellness of a child by encouraging them to choose their gender preference at such a young age. As a child I was a tomboy growing up and liked to play video games and sports with the boys in our neighborhood and didn’t like to play dolls with my sisters. My parents and teachers knew these things but did not encourage any thought around gender preference but encouraged me to do what I was interested in. I am grateful that I never gave any thought to the things children are exposed to today, which would have led to confusion and anxiety. I am now a well educated, well employed FEMALE engineer and work in the data science realm with many male coworkers. Being interested in topics that are typically associated with males does not mean that one should be encouraged to choose a different gender, but they so often are today at too young an age to fully understand. They should be taught that they can be whatever they want to be and their gender does not prevent them from doing so. I grew up always fully confident in my identity, and parents are most capable of handling any situation in this realm, not schools.