The video informing a user about signing into Office365 must be disabled.

Office 365 is a subscription-based service which offers access to various Microsoft Office applications. Access to Office 365 will not be permitted; only locally installed and configured Office 2013 installations will be used. Since the ability to sign into Office 365 will be disabled, this policy, which determines whether a video about signing into Office365 is played when Office first runs, will also be disabled.