I’m not totally sure if you are looking for this, but you should open user’s profile and click admin, scroll down and you find somethng similar:
After given timelimits an user can’t do that, but an admin must do anonymizing. That is actually quite common solution, because it is inreversible action and users who want to delete account can be quite pissed off. And regret next day.
Total deletion is impossible when there is content. And that is good solution. Of course admins must check that there isn’t eft any personal references.