We can do searches for content by user with the syntax user:xxx
where xxx
equals the user number. However, this does not work with deleted users.
This could be useful for the same reasons the user-based search is useful in general, of course. In the case of deleted users, this can sometimes be especially useful, though; for 10k and diamond users doing moderation duties, in particular.
In fact, this would also be a great thing to simply link directly to on the moderator's page for deleted users (perhaps in conjunction with showing deleted posts)