Tandora.
This is based in law and evidence from the collapse of the Tavistock and the interim Cass report.
It's progressive guidance to keep all children safe, including those who are under gids (who you'd describe as trans kids I imagine.)
You have a right to be offended, and a right to have your belief that gender identity is a tangible part of someone.
The evidence is that that belief doesn't help children who are questioning ideas about sex and gender. Mainly as it's sexist, inflexible and tells them adults agree there something wrong with their bodies.
Never a helpful message.
The evidence is that immediate affirmative approaches do not help these children and lead to irreversible damage. (Adults too.)
I'm not sure why you disagree with gender questioning children deserving the best care, and indeed all children, including girls who are unfortunately subject to the risk of sexual assaults at school. (Hence allowing them privacy from boys.)