Tombstones lose their last words
Delete your account and the replies other people answered stay put, but the text behind them is gone. The site now blanks the body, mentions, link card and search vector instead of just hiding them.
Delete your account from settings, then reopen the thread a friend answered. The tombstone still sits there under [deleted] with the replies underneath, but the words it stood for have gone. The body is an empty string, the mention list and link card pointer are null, and the search vector is gone.
Credit goes to sulimanbenhalim, who made account deletion finish the job. The same database update that strips the author now clears four columns. They are the body, the people you mentioned, the 1,536-number embedding that powers search by meaning, and the pointer to the link card. A one-time migration sweeps the replies already orphaned by past deletions and blanks those four fields too. Live posts and ordinary deleted posts keep theirs.
One catch. Unhooking the link card does not delete it. Cards are shared by URL, so the row holding that page's title, description and image stays for every other post that linked it. Your tombstone simply stops pointing at it.