This is way overhyped. It's barely more than “gay people exist, don't bully them” most places. One lesson in PSHE class – maybe two or three, if you get lucky and your teachers decide to teach you about binary trans people too, or if sexuality is mentioned in the Equality Act lesson (which mostly focuses on disability and maternity leave).

> opinions about sexuality are being presented as fact

By this logic, we should ban other children from talking about their religions in schools; they're likely to say things like “Jesus is God” or “God isn't real”. It's unlikely a religious child would get particularly confused with a teacher exposing them to different views on morality, given how much they're already exposed to that.