You are wrong. There is not a lot of difference between trending and open-source app filters. But I can understand why you think they might be different. In reality, an app filter will always be opinionated in the exact same way trending is.

In fact, most decisions any client makes ARE opinionated. Simple things like how to display notifications, reactions, zaps, reports, posts, user profile pictures, etc are ALL opinionated. These are not even filters, they are just design decisions. They always benefit the user set that fits in with the design better. Those users get more visibility just because the design helps their style of posts.

This is all factored by time. You can always say that some users get more features than others. By that difference, you can say that apps are always censoring one group of users when devs are not working for them in a given version. It can all be bundled together in a "censorship banner".

In summary: if your app uses a card layout you are "censoring" users whose posts fit better in a full-bleed design.

That's just the way design works. By these extending definitions of "censorship", every choice is "censorship" to somebody.