User Configuration > Administrative Templates > Microsoft Office 2016 > Tools | Options | General | Web Options...
User
HKCU\software\policies\microsoft\office\16.0\common\targetedmessagingservice
This policy setting controls whether dynamic lifecycle messages are displayed in Office applications. A dynamic lifecycle message appears as a notification in an Office application. This message is similar to a default lifecycle message, but provides additional information. For example, a message that reminds users to renew their subscription that also includes information to help them renew. Office periodically connects to the Internet and contacts Microsoft to determine if there are any relevant messages to display. If you enable this policy setting, Office won’t check for these types of messages, but, default lifecycle messages still display in Office applications. If you disable or don’t configure this policy setting, Office checks for these types of messages and displays them.