Latest Beta Channel update, version 16.44 (20111807) and newer, now has support for Shared Calendars. For those on Beta Channel, please update and view/open Shared Calendars. Please report any issues via Help > Contact Support. Thanks!
An error occurred while saving the commentMatt commented
When moving to 'new outlook' for Mac, keep existing shared calendars when migrating to the new client.
All other settings seem to have been persistent, but shared calendars have been dropped.