Last week, we started to use / test this feature. I set up a meeting (Outlook) and invited the Room Resource (Webex Board).
All attendees including the room (I had a look to the room‘s Exchange calender). Got the meeting information via Outlook.
We extended the meeting using the Room Navigator. After we get saw that everything was ok (extended meeting was shown on room navigator) I then looked at the calendars again.
Room calendar: a new 15 min meeting with me as appointment sender.
My calender: only the "old" original meeting.
Other invited users: only the "old" meeting visible.
I think it would be much better to extend my original Outlook appointment via EWS and send an update to all the users.
So we only have one entry in the Rooms Resource Calendar and the calendars of all the attendees get an update for the meeting.
If someone else uses Outlook to set up a new meeting, using the outlook organizer to see if a colleague is available is not hit by an extended meeting not synced to all calenders.
Second 3rd party room booking systems can read the room calenders via EWS and gets only one entry for one meeting and not 2 or more.
The Room Resource account most likely does not have authorization to modify the Booking Owner’s calendar. That is why we create a 2nd meeting to block to room and not modify the booking owner’s meeting.
You could imagine that the person in any of the rooms joining the scheduled meeting might not be the booking owner and that user likely should not have authorization to update someone else’s meeting invitation. That is why it is a new meeting from an admin-configured scheduling account.