As an on-prem Exchange customer who doesn't allow calendar access to user mailboxes, as we migrate from Webex Meetings to Webex, we're finding that the meetings that "sync" to the Webex application exclusively use the Webex calendar database.
This means that if users are invited without using the Outlook plug-in or Webex site, the Webex app doesn't scrape the local mailbox for meetings that might just have a Webex URL in the body of the invite.
Similarly, if a meeting is declined/cancelled/moved, the end users is often prompted to join a meeting that isn't there. Again, when users rely on their calendars as the source of truth, but Webex isn't aware of these changes that happen in Outlook/Exchange.
This worked perfectly on the Webex Meetings application which simply used MAPI to scrape the Outlook calendar. Please bring that to the Webex [formerly Teams] app!