I've made it so that when someone deletes their own post it is still viewable, including the comments. The post author and body will NOT be visible. Deleted posts will not show up in communities, search results, etc just as before - you need the URL of the post to get to it. Bookmark a deleted post within 7 days or it will be deleted for real.
Ask your instance admin to upgrade to v1.4.4. Chances are they'll be on 1.4.x already so this will be easy for them.
What happens if I'm the only one to have bookmarked the post, and then I unbookmarked it after a year? Is that post deleted or will it still be accessible as long as I have the URL?