Whether they call it shadowban or not, no platforms like boring content. If your page keeps posting the same recycled thing every day, people themselves will stop engaging before any algorithm even acts. I doubt if the social media companies care whether AI assisted you. They only care whether users keep scrolling or they stayed because they are interested in your content. If the audience are ignoring your posts, your reach will naturally drop. It's as simple as ABC. I think mixing original ideas, personal examples and useful information still beats flooding your timelines with generic content.