Here's one possible approach: you can have a secret algorithm OR platform immunity, but not both.

News outlets don't have to publicize their internal editorial decisions, but they are responsible as publishers for the content they publish and can be sued if, for example they publish something false and defamatory.

Isn’t that just the news? As in what they publicize is their internal editorial decision?

Aside sticking a camera in the newsroom and livestreaming all day, what would this entail?