Submitted this back in January in Feedback Assistant but no response.
After installing Ventura all of my existing Exchange Calendar events that were set to “Show as” Out to Office now show as busy. New events are also missing the option to choose OOO. iOS works fine. I tried removing the account and adding it back but others are experiencing the same per: https://discussions.apple.com/thread/254336452?login=true
The option is not available in iCloud calendars in macOS but never was in past releases. If I set it to “Away” in Outlook.com which is the new denomination in Outlook it shows as busy on macOS Calendar. SS attached
