You are actively advocating for schools to do this.
If so, then you are arguing for schools to not exist.
Your children are your responsibility, not your property. When you sign your child's birth certificate, you are effectively signing a contract with the state accepting certain responsibilities. If you renege on that contract, the state can take your child away. One of your responsibilities, one of the things
you have to do in order to raise your child, is to send them to school, or at the very least to ensure they are taught in accordance with a standard curriculum.
A parent who wishes to intentionally retard their child's natural sexual development
is neglectful. Any belief that doing so will protect those children from abuse or even deter them from risky sexual behaviour is simply wrong. There is no ambiguity in this issue at all, which is why your argument is ultimately just a vacuous appeal to popularity.
At the end of the day, children will grow up. They will have their own lifetimes full of unique experiences and will come to their own understanding of the world they live in. As a parent, you have enormous power to shape the person they will become, but at the end of the day in order to become a fully realized individual your children have to leave you behind. Hiding basic features of the world from them to try and retain control over their lives is sufficiently malicious that I would question whether the word "neglectful" adequately covers it.