You cannot isolate good and bad examples of censorship that easily either, because it denies users information on what information they're being denied. This hypothetical site is hardly going to tell users that it's hiding the fact they're killing their babies from them; it's more likely to frame it as protecting them from industry propaganda, exactly as you argued they should be allowed to. It's only from the outside perspective that this is obviously terrible.

(This is, in my experience, a general principle of site-based censorship. For example, if I had a dollar for every regular of every feminist community who was sure the site moderators were protecting them from the oppressor, when actually they were protecting the site owners from criticism and dissent by women more oppressed than them who they were rather spectacularly failing to represent...)