I have something in my mind and I want to be reassured:
If the owner of a locked account send an appeal from a new email, will you unlock his account?
I believe it would depend on whether or not the user has a signed message, there has to be something with which to prove that you indeed owned that account.
It is very thoughtful of the admin to be lenient and consider accounts without signatures. Every user however should endeavour to sign a message as soon as they can.