So a law against lying about what you are?
I do not have an issue with that.
Parents can play make believe nonsense at home but when their child is in school he or she should enter reality.
Whats weird is the obsession around thinking it's "parents transing their kids".
That's almost never the case. You don't have to be an adult to have your own agency over yourself. It's not the parents or the teachers. Somehow a lot of people don't seem to think that any kid or teenager can think for themselves and decide for themselves what they are.