Outlook 2016 shared calendars not updating properly
The appointments from that calendar will have to be migrated to the new calendar.
Using Peeks is easy: click on Mail to open the Mail module.
Pinning the peek to replicate the To-do Bar (which we've had for the last two versions) is a multistep process.
You need to pin each peek individually (and unpin individually) and once pinned, it applies to the current folder type only.
The Calendar peek is limited compared to the To-do Bar: You can drag to the word "Calendar" (seen in the screenshot) to open a new appointment with 'now' as the default time and date.
Right-click & drag a message to "Calendar" and you'll see options to create new appointments as text, shortcut, attachments etc.