Meeting Creation and Tracking

Thanks again for your response. Here is a little more information that I've gathered through the course of working this ticket with support. This is all reproducible across all tenants that I've tested this on.

There is definitely an issue related to "Require/Don't Require Response," but the path to that setting is flawed. Here's why.

There doesn't seem to be a way to control the Response Required setting at the time of meeting creation, but your environmental state will affect its setting. The variable is whether you are showing multiple or one calendar in the web view when you create the meeting.

If you are showing your own calendar in addition to the group calendar and you select new meeting and you set the calendar to the group calendar, the meeting will be created with No Response Required.  

If you turn your own calendar off and only show the group calendar when creating the meeting, the meeting will be created with Response Required and things will work as generally documented (aside from No Response which still doesn't behave as I believe is documented).

Given either method, log in as an invited member of the group and Accept or Decline the meeting. Go back to the originator's identity and check the meeting. Meetings created with multiple calendars turned on initially will not display attendees properly. Meetings created with just the group calendar turned on will display responded attendee, but not No Responses.

The behavior is being escalated via support to the next level so if you or anyone agrees with the issues feel free to ping support. My assertion is that it makes group meeting invites pretty worthless without accurate tracking of attendees.