According to the compatibility table in this Microsoft website version 1.4 of the Javascript API for Office, is compatible with Outlook for Mac 2016.
However, I'm using the latest version 15.33 of Outlook for Mac (not insider) - and when I change
<Requirements>
<Sets>
<Set Name="MailBox" MinVersion="1.3" />
</Sets>
</Requirements>
in the manifest file to 1.4 the add-in disappears from Outlook for Mac - my add-in displays a side pane on the composition form of an calendar event.
Why is it that?