Meaning: schools have the right (and responsibility) to take steps necessary for the safety of children, but those rights are rather limited compared to those of parents, because they must also satisfy the limits set by constitution for all acts of the state and its representative. Banning books is an excellent example since it is almost the textbook definition of a restriction of free speech at the same time as having exceptionally weak arguments for its necessity, ostensibly to prevent psychological harms, which is a dubious concept to begin with.
Does it? Is there actual evidence of harm from having these materials available, or is this really just pearl clutching?
It really doesn't. School is one of the best places we can have people encounter challenging idea and works for the first time. If we coddle people on school and then they are exposed to those ideas on their own (which they will be) then they have fewer resources to aid in processing those ideas and are more likely to end up confused and misinformed.
I owe my entire current mentality to the books and literature I found on my own beyond the parent's wishes. They're good people in many ways, but having that sanctum to explore other experiences was critical.