It's also not for the kid's parents or teachers to label him/her. That's why there shouldn't be any invasive procedures until the kid is mentally capable of making that choice. Not to mention that making an informed choice here is literally impossible if the kid didn't even get a chance to experience their biological identity - you don't really know what it means to be a boy or girl until you go through puberty yourself.
Again, gender identity and gender expression is something that is up to the individual. You don't label someone as trans, you ask them how they identify, just as if you were asking what name they go by.
You and I are on the exact same page. If you still don't think so, please make the distinction clear.