See Attendee Changes Made Through the API on Microsoft® Calendars

Now when changes are made to the Attendees field through the API, it’s easier for sales reps to see those changes on their Microsoft calendars. That’s because changes sync from Salesforce automatically. Previously, changes made through the API didn’t sync unless triggered by a change to an additional field on the event. Considerations for attendee status sync (Accepted, Declined, or No response) still apply.

Where: This change applies to Lightning Experience, Salesforce Classic, and all versions of the mobile app in Professional, Enterprise, Performance, Unlimited, and Developer editions.

How: Attendee statuses sync from Exchange to Salesforce, but not from Salesforce to Exchange. Be wary of creating API flows that update attendee status in Salesforce for users set up to sync both ways. Eventually the original Exchange status overrides the update made in Salesforce.