If it's just school libraries, it's fine. I was able to easily determine what my kids were reading on our weekly trips to the library. I didn't have visibility to what they were reading at school.
I appreciate the TV-MA ratings on TV shows. I don't know why I'd have a problem with someone vetting material being presented to elementary students.
Now, I'd certainly want to make that process transparent and to have mechanisms in place to overturn decisions made by the representatives who are making those decisions.