Earlier quoted context omitted.
From what I understand, if you log back in to your account within 14 days* then the delete request is cancelled and everything goes back to normal. It makes me wonder if Facebook had a bad couple of days of people deleting their accounts and Mark Zuckerberg thought "Right, we've got 7 days to fix this and get them logging in again, let's get to it!" * I could have the precise timeframe wrong
This is unfortunately a common misperception. If you deactivate your account you can bring it back. If you delete it the data is deleted.
Wrong. If you deactivate your account, you can bring it back. If you request it to be deleted, you have 14 days to cancel that request (by simply logging in) before it's deleted. Once it's deleted, that's the end -- you can't bring it back.
(edited to make clear which part of your comment is wrong)