A feature like this would be great to have. We currently use GTW for board meetings that are open to the public. This allows us to promote or allow attendees to speak during public comment and then place them back on a hard mute. However, when it comes time for a closed session, we have to have all our board members disconnect from GTW and jump on a GTM where we can see who is exactly in the GTM and lock it down. After the GTM everybody has to jump back on the GTW to report out. Pretty cumbersome stuff, GTW -> GTM -> GTW. 2 sets of invites for panelist to manage.
It would be great to be able to dismiss all attendees, even those on the phone, to a waiting room so the panelist, organizer and co-organizers can conduct a meeting in private and then allow attendees back into the webinar when the private meeting is over. We would pay for this feature!