Add this to the pile of weird changes since Office 2011:
I discovered that if you install Office 2016 on a Mac that has never had ANY version of Office on it before, the Sharepoint browser and webkit plugins are not installed in /Library/Internet Plugins/ nor anywhere else for that matter. I used Pacifier to confirm that those plugins are not even part of the installer package. If a user on such a Mac logs into Sharepoint and clicks on a file listed on any document library, the file is only opened in-browser. There is no option to open the file using the actual Office 2016 apps.
If I take the Sharepoint plugins from Office 2011 and install them where they go and then repeat the process of clicking on a file link within Sharepoint, they DO (usually) open with the Office 2016 app. I have 1 Mac that will only attempt to download the file to ~/Downloads - it doesn't open in the document in-browser nor does it open with the Office 2016 apps. I'm not sure what to do with that Mac yet.
Can someone explain the way it is SUPPOSED to work with 2016?