What would happen if a child brought those not-banned or not-censored books to a library/school where they have "forgo those specific books"? What would the reaction be?

I feel like if they'd still let the person read the book by themselves, and freely share it with others, then indeed it's merely a curation choice. But, if I'd expect, they try to prevent this person from reading their own brought book or sharing it with others, then I think it's fair to say that book been banned and/or censored, at least in that particular location.