snow2462 I've not checked in details but likely the "hidden" posts are never returned by the API when you are not allowed to see them. They are probably not even returned from the database query via the use of the ScopeVisibilityTrait
.
To show them as hidden to everybody, you'd have to change the view
permission on hidden posts to allowed for everybody (via a policy), but then change the serializer so you hide the content of the post only to those users (otherwise anybody could get the content of those posts via the API).
Another option could be to create a new post type for deleted post ghost that would only contain the author or no info at all, and automatically publish one whenever a post is deleted (and place it at the right place in history of course). Then simply make/let that post type visible to anybody.