User Configuration > Administrative Templates > Microsoft Office 2016 > Miscellaneous
User
HKCU\software\policies\microsoft\office\common\userinfo
This policy setting controls whether Office uses the user name and initials of the user currently signed-in, or the user name and initials that are specified in the Options dialog box. If you enable this policy setting, regardless of any user currently signed-in, Office uses the user name and initials specified in the Options dialog box. If you disable or do not configure this policy setting, Office uses the user name and initials from the information provided by the user that is currently signed-in.