Hi ​@People66572 - Thanks for reaching out!

Adding an event that overlaps other events in the Calendar would not automatically remove the overlapped events. However, if they went through and deleted or declined them in their Calendar, Calendly would cancel the events and send a notice to the invitee as long as they have Sync Cancellations enabled on their Calendar Connections page:
 

They can always check their meetings page to ensure they were cancelled fully.

Let me know if you have any questions!

Thank you! I serve as an admin for a group of providers, so I don’t have direct visibility into their calendars. Is it possible for an appt to show up on a client’s calendar if we no longer see it in the provider’s list of upcoming appointments (the view below)?

Got it! In this case, if the event does not show up in your upcoming appointments, that meeting is most likely cancelled. So depending if the event was declined or deleted, the same would show on the clients calendar. This is more handled on the calendar providers side as we mostly just handle the cancellation notification.