Sure. And that is up to the parents to decide when their prepubescent children get exposed to sexual materials and in what way. If you want to make an argument for schools picking up the slack for lazy, confused, and stupid parents I think there is one to be made. But it's not the kind of shit we have been seeing recently.
Personally I believe that you cannot maintain a child's innocence with ignorance. I have three children, all over the age of 23 and none of them have children yet due mainly to my policy.
One is straight, one is bisexual and married to a woman, and the other is non-binary. They knew everything they needed to make informed choices about their sexual partners and their personal choices and I love each of them dearly, they are supported in everything they do, and are all very creative and successful.
I do not want their children to have to deal with the things I have heard read at school board meetings, that the administrators put in elementary children's rooms.
The graphic depictions of sex are above their age group, and the conflation of violence with it is not a healthy way to socialize a child to sexuality.
Maybe you should do some searching so you know exactly what is being put into children's classrooms and how the narrative has twisted in the grip.
What is being made available is more like exposing children to rape (and in some cases it is exactly that in literature) than barnyard animals. If you support this kind of thing then we will remain opposed. Damaging children intentionally is not something I support.