I've never had to face what it's like to be transgender. But I am what most would classify as "bisexual."
I didn't tell my mother about my sexual orientation until I was pressured to by my extended family at the age of 17. My mum is a religious Conservative who believes the LGBTQI+ community is a bunch of brainwashed kids having sexuality forced upon them from TV shows and drag queens. I didn't feel comfortable then, and it was scary, and the more I get to know my mum, the more I regret telling her. Now I know that every time she spews bigotry, she's doing so with the knowledge that I'm in the group she's targeting. Her knowing that her daughter, whom she raised and thought of as "normal" didn't stop her from spreading misinformation and fear-mongering. She treats me well, but she doesn't accept my whole self no matter how much she says she does. She still disregards my identity as nothing more than a trend for the mentally ill. She once told me, "Yeah, yeah, I know you think you're bi," meaning she doesn't actually believe I am but that I have been brainwashed to think I am.
So even though it's not the same experience, I understand what it's like having an extremely personal piece of information about your identity -- that you're still getting used to yourself -- being shared, with scary potential outcomes. I can imagine how even scarier it would be for someone in this situation to be transgender. While the general public has made some progress with the LGBTQI+ community, transgender people are still not safe.
Knowing about cases like Brianna Ghey (she was murdered by "friends," not her parents) breaks my heart. I can only imagine how terrifying it is to just exist as a transgender person in this world. Just because someone is your parent, doesn't mean that they will protect you any more than strangers or friends. Sometimes parents don't have your best interests at heart and can be your biggest bully.
Having such danger forced upon a CHILD is absurd. If it were up to me, I would leave it up to the student involved whether or not to share this information with their parents. It's not a medical condition, and children aren't properties of their parents. While I understand that some would want to be there for their children, some don't love their children unconditionally and would choose religion over their children any day. I think a student would know more about their parents' likely response than the school staff (who only see the parents for brief moments) and the government. I don't feel comfortable with this decision excluding the students' autonomy. They're not pets; they have a voice and personhood that should be respected.