This is not and never can be a freedom of speech issue. In this case it is a teacher or school board deciding what others are to be taught so by its very nature even if that individual has freedom of speech the students do not. In a school freedom of speech is limited; students cannot say what they want when they want, and the same is true with freedom of information; they cannot learn what they want when they want. This is because school is to give them a basic grounding in everything they need to know rather than it being a place where the student can pick and choose.