It would be treated similarly to a 'hidden' post, in that wouldn't be public and would only be visible to editors and mods. We can go back and reshow posts that aren't approved the same way we can with hidden posts.
At the moment it is possible for post authors to go back to their 'rejected' posts and click reshow, which sends the post back to the approval queue. This may be useful if they wanted to edit the post to make it fit the rules.
