User Configuration > Administrative Templates > Microsoft Office 2016 > Tools | Options | General | Web Options...
User
HKCU\software\policies\microsoft\office\16.0\common\general
This policy setting controls whether Office-provided templates (from Office.com and shipped with the Office clients) are hidden on the Office Start screen and in File | New. If you enable this policy setting, users will not see any Office provided templates on the Office Start screen nor in File | New. If you disable or do not configure this policy setting, users will see Office provided templates on the Office Start screen nor in File | New. Note - enabling this policy setting does not prevent users from downloading templates from Office.com using their Web browsers and does not prevent users from using Office-provided templates installed on their hard drive using Windows Explorer to launch those templates.