There are several parts of this proposal that I'd like to go over. For one, forcefully outing kids to their parents is setting up some of them to be abused and murdered by relatives that don't understand or choose not to. Their suffering would be on you. Furthermore, not every kid who thinks they might be trans actually is, they could be just seeing how different styles or pronouns fit them in the safety of school. And by forcefully outing them, you might take away that experimentation, putting even cis kids in danger. Also, where is the line drawn? If a young cis girl isn't performing femininity to your standards, does she get "outed" as trans? Is she no longer allowed to use the bathroom that she feels most comfortable using? Is she kicked off of her sports teams? It doesn't make any sense, and is frankly just a disgusting way of controlling kids.
As for the restriction of using a preferred name, that also makes absolutely no sense. I remember so many kids asking to be called nicknames or something other than their legal names, and more often than not that made it easier on the teachers. Many kids asked to be called something else if someone shared their first name in the class. This proposal would completely take that possibility from them, leading to more issues. Then there's the fact that some people never even really go by their legal names. I knew someone who, from being a small child, they had a nickname and pretty much everyone called them by it. And none of that is even taking into account the fact that being called your deadname on a daily basis, hurts. It frankly should be avoided at all cost, or the person will just come to associate that name with terrible things. That's what happened with my deadname. My mom refuses to use my name, and I feel genuine hate towards that name instead of just thinking that it wasn't for me, like I used to.
Protect trans kids, protect cis kids, but those protections DO NOT have to come at the cost of the other. Actions like this will end in suffering and death for far too many children.