See Group Calendar Meeting Response Comments from Attendees
See Group Calendar Meeting Response Comments from Attendees - When a user responds to a Group Meeting request, we would like a Group conversation to be created to track the responses and related comments, or add the comments to the Group Meeting tracking information.
This problem causes no end of confusion. It's poor UX for a user to use "Edit the Response before sending" in Outlook, type a message and send it, and then have it ignored by the auto-processing. The user invariably thinks that the person who created the meeting on behalf of the group has seen their message, and the person who created the meeting thinks that there were no attendee comments.