Describe the bug
Comment threads remain active even if all comments are deleted

I added an answer suggesting this bug was fixed, but the poster of the Meta question explained that they can still see the deleted thread even after I added a comment and deleted it to make the thread disappear. It appears that the empty thread containing only deleted comments is hidden from all non-moderators except the poster of the post on which the comment thread appears.

To Reproduce
Steps to reproduce the behavior:

1. Add a new comment thread on a post of your own
2. Delete the comment so the comment thread is empty
3. Refresh the page so the comment thread disappears
4. Click on "Show more" that appears where the comment thread would have been
5. See the empty comment thread

Expected behavior
Since the poster of the post cannot see any of the deleted comments in the empty thread (even their own) the empty thread should be hidden from them, as it is from everyone else (except moderators).

Screenshots
See my answer on the Meta post.