No, you don't need to constantly unlock your Hub or keep it open. That's the benefit of the Alby Cloud service.

In this specific case we sent an email to inform about a necessary update on Monday. After an update and a restart the Hub needs to be unlocked. The update was done on Wednesday. That's why you received this email.

Going forward we try to keep required updates to a minimum so that you can decide when to update and unlock the Hub.