I too was directed to this post to “uplift” it. However, it does not solve my problem of being able to setup a meeting that allows for multiple attendees outside of my organization. We currently use Microsoft Bookings for the purpose of scheduling group demos. We cap the number of attendees to 15. The meeting shows as an available time slot up until the maximum number of attendees have registered for it. If maximum number is reached, it no longer shows as an available time slot, exactly as one would expect just like scheduling a one-on-one meeting.
Max Attendees Setting
If one attendee cancels his/her registration, it does not cancel the meeting for everyone. Only the organizer can cancel the meeting. If the organizer cancels the meeting, it would send cancellation to all attendees.