I'm not sure I agree about the library profession being anti-censorship. They think they are, certainly.They love to promote Banned Book Clubs and Freedom to Read week.
But the profession as whole,or at least the public side, is quite extreme in terms of its political imbalance. Even in some cases to the point that you see organizations like the American Library Association explicitly becoming involved in a partisan political way.
But there are some very weird blind spots when it comes to things that offend their own political sensibilities, which a lot weirdly assume are somehow neutral.
What I see though is they don't try and "censor" the books like this directly. Instead they refuse to purchase, or weed them, on the grounds that they are unscientific or contain incorrect information or - ironically - are politically biased.
The weirdest one I ever saw was a librarian on Reddit saying he would not accept a donation of Bibles from someone - not because they didn't need them (which tends to be the case unless they are unusual) but because the individual had not also offered to give other religious texts "for balance". In truth, he was bigoted toward Christians, was the real reason.
That kind of thing goes under the radar though and can't be challenged ascensorship.