Actually, you can, but it’s logged as a “show email” action. Go to the single admin user page and it shows up where Google / other associated logins would be.
Edit: Of course, side channels (posting time, writing style) can be used, as you see on 4chan etc, but these are mitigated by only using a particular “anonymous account” for a max 24 hour period - once that cycles, the number increments again and you lose public linkage.