We use Sessions for reviewing massive drawing sets collectively as a team. There are many instances that we need to inform users of some changes made, documents added, etc. that impacts their work. There does not appear to be an "email all attendees" option, which would be very useful.
Not all attendee lists are the same between all of our sessions. Some utilize different user sets based upon the content being reviewed, so one cannot assume we can just have pre-defined external distribution lists to use. Peers may add individuals as needed after the session is initially generated with defined user lists.