Outlook 2016 shared calendar doesn't show appointments
Outlook 2011 users must be granted "Reviewer" access to another person's calendar to be able open that calendar and view details. If a user sets permission levels only to allow free/busy or free/busy limited details, an Outlook 2011 user will not be able to see any details of the shared calendar.  

PC users must grant "full details" to the Outlook 2011 user. Mac users must grant the "Reviewer" role to Outlook 2011 users. 

Basic free/busy time viewing is only viewable via the Outlook 2011 Scheduling Assistant feature, or via OWA. (Note: Outlook 2011 users who have a "Reviewer" role may also be able to select another users name within the Send As / From drop down menu. Unless you have explicit permissions to Create Items within the selected users mailbox, Exchange will not allow you to send on the behalf of that person).

Above is true for Outlook 2016