This gives me some weird feelings. I mean, if you ask a website to turn some content "unpreferred" without user consensus, isn't that also some type of censorship? In fact, many Chinese websites are doing it right now, and it's very effective in terms of censoring contents.
However, I support the idea of content flagging, but instead of making them "unpreferred", maybe add a mark saying "Propaganda from XXX" so people can be more cautious about those information themselves?