Using older versions of Outlook for Mac for personal email and calendar
This finally does seem resolved for me, after 3 days (100 emails) of outage/delay. My experience as end user: I restarted Outlook app several times during the outage; last time showed outage behavior (user connecting to Exchange repeatedly), but now I finally I do have updated inbox without additional Outlook restart, which I suspected would happen since the problem seems to be on Exchange server, but it may be useful to others to know end users don't need to restart Outlook to benefit from unfking once it finally reaches your Exchange servers.