So, they will be teaching gay history. Whether you want to recognize it or not, gay individuals have made huge contributions to our history. Teaching the history does not make a statement regarding the moral right or wrong of homosexuality. That is still up to the parent to teach. There you go. Your rights have not been taken away, unless you want to retain the right to have your child selectively educated and given a distorted perspective of history. In that case, you still have the right to homeschool.
BTW...my "you" is a generic and collective one.