AutoUpgrade is a good thing. What does it do?
When a renewed or revised license file is deployed as we describe in its accompanying short note, then anyone who already has a valid (i.e. current) revision of your license installed won't see the installation of the new revision ... it will happen automatically and silently.
But those users and visitors with an expired or with no license installed won't benefit from AutoUpgrade and will be prompted to allow the installation of the license in the usual way.
So if you're going to renew a license, don't leave it to the last minute!