An event management system is configured to host a collaboration event that includes first and second event endpoints that provide respective first and second sets of audio/visual (A/V) media streams to respective first and second sets of attendees during the first event. The event management system is configured to, while hosting the collaboration event, reconfigure the collaboration event to cause a third event endpoint to provide a third set of audio/visual (A/V) media streams to at least one of the first set of attendees.