If you change the post number in any question URL to a number of a deleted question, you will be redirected to a 404 page, but the URL in your address bar will change to contain the title of the deleted question.
Example URL, try it in private browsing mode: https://meta.stackexchange.com/questions/339451/
Works with "q" and "a" links too, but not "posts" links.
This works while logged in, but the fact that it also works while logged out, in my opinion, is much worse.
