When changing a recurring appointment series, past occurrences should never be changed at all. Any change to a series will generally be intended to reflect a change in planning that only applies to the future; past occurences are a record of what was planned and occurred in the past. It makes no sense to apply series changes to the past. Best-case scenario: like Google Calendar, offer the user a choice between 'Series/This occurrence/All future occurrences' when modifying a series or an occurence of a series.
This feature request goes very well with Retain exceptions when editing a recurring series - Microsoft Community Hub, Recurring Outlook Calendar Entry End Process - Microsoft Community Hub, and Outlook - Edit/Delete Future Events in a Series - Microsoft Community Hub.