You can download the Office 2016 (or 2013 if thats what you're using) admin template files here: https://www.microsoft.com/en-us/download/details.aspx?id=49030
Microsoft 365 Apps for enterprise, Office 2019, and Office 2016. Always download the LATEST admin templates to a location of your choice: Administrative Template files (ADMX/ADML) and Office Customization Tool for Microsoft 365 Apps for enterprise, Office 2019, and Office 2016; Select the Download button. Select either the x64 or the x86 build. I was interested in the location of the Default Location for the user templates in Word 2016 for Mac. According to the help in word it states that the default location is '/Users//Library/Group Containers/Microsoft/Office/User Content/Templates'. However, if you go hunting for this location with the Finder or look up the location in Word Preferences File Locations the actual location is '/Users//Library/Group Containers/UBF8T346G9.Office/User Content/Templates'. The location is C: Documents and Settings Username Application Data Microsoft Templates Document Themes, as shown in Figure 2, below. Figure 2: Location of Themes in versions of PowerPoint on Windows XP Office 2016, 2011 or 2008 on Mac OS X. Although you can designate a My Themes folder in Office versions of the Mac, there is a default location that’s used if no designated.
Import them into GPO and then create a policy and change the 'Workgroup Templates Path' to your shared drive location under User ConfigurationPoliciesAdministrative TemplatesMicrosoft Office 2016Shared Paths
After that, if you want the default tab for creating a new file to be the 'Shared' tab that Office creates when using shared templates then create registry key:
Office 2016 Mac Os
HKEY_CURRENT_USERSoftwareMicrosoftoffice16.0wordoptions
Office 2016 Mac Key
DWORD: officestartdefaulttab
Value: 1
Office 2016 Mac Template Locations
This one is for word, but is similar for each of the programs.