Currently using the Outlook Connector and "Update Event" you do not get the option to choose 'added attendees' or 'all attendees' on the email updates. Currently if you use "update event" it will send an email update to all attendees. This behavior is different with the desktop and web version of Outlook where you can choose to send to all attendees or just the added attendee. If we can have expanded ability to match the same behavior in the Outlook web client it would be extremely beneficial to customer workflows.
Alternatively, possibly add an option to not send updates to all attendees other than those newly added.