I don’t think so. Mirror is how the upstream repository and the repository in the library are kept in sync. With mirror, I think, you are supposed to see an exact mirror of the upstream repository in the local katello repository.
However, with content views and published versions, content which may have been removed upstream, may still be used by a content view. Only later, when all content view version which have used the old content have been purged, delete_orphaned_content can eventually clean that up and remove it from the system and database.