User Configuration > Administrative Templates > Microsoft Office 2016 > What's New
User
HKCU\software\policies\microsoft\office\16.0\outlook
This policy setting controls whether the What’s New information is shown when a user opens the desktop version of Outlook for the first time after Outlook has been updated with new features. By default, the What’s New information is shown. If you enable this policy setting, the What’s New information isn’t shown. Also, the What’s New button in File > Office Account is disabled. If you disable or don’t configure this policy setting, the What’s New information is shown. Note: There are separate policy settings for Word, Excel, PowerPoint, Outlook, OneNote, and Visio.