Microsoft have recently deployed a new cmdlet to Office 365 tenants: Remove-CalendarEvents. This new cmdlet is only available in exchange online at the moment, it allows admins to remove calendar events with participants, from a mailbox.
Below are a couple of examples to have a look through:
Remove-CalendarEvents -Identity chris@contoso.com -CancelOrganizedMeetings
If you were to run the example above it would cancel every meeting in chris@contoso.com’s mailbox that is scheduled on or after today’s date.
Remove-CalendarEvents -Identity “Angela Gruber” -CancelOrganizedMeetings -QueryStartDate 11-1-2018 -QueryWindowInDays 14
This example cancels meeting within a specified date range within Angela Gruber’s calendar. For example if Angela was taking some annual leave you could remove meetings from the her calendar for the dates she is off.