The button is used to prevent an early, accidental, unlocking of your account.
For example, if one of your Recipients clicks the "Unlock" button from their Recipient Management Center, you will be notified by email. In order to cancel the unlock request, you would click the button. The total number of unlocking requests would be reset to zero. At this point it would be a good idea to talk to the Recipient who submitted the unlock request, and explain to them that completing this action should only occur after you pass away.