In my school, it was rather difficult to find anyone bullied for their sexuality. Usually they were left alone. Those who got bullied were either nerds or on the bottom of the popularity totem pole, which is decided when you first started (which for me was 1st grade). It didn't have anything to do with who I liked, it was just people asserting their superiority (popularity) over me and anyone else.
When the whole sexuality and identity crap is pushed continuously into your face though, even as a child, it makes you feel less like a human being and more like something else that needs to be acknowledged, which is especially dangerous when the adults try to push it on someone when they even think they're something other than straight and attribute all their life's problems to that. It's invasive, annoying, and doesn't solve anything, period.
Definitely anything like that should be aborted in school period. It shouldn't be up to anyone to impose stuff like that into anyone's life, especially a minor. Let them develop on their own. Meanwhile the whole acceptance thing comes naturally except for popularity-superiority. If they don't get bullied for their sexuality, they'll get bullied for something else.
