When a user is deleted from Jira, the Teamployees plugin ensures that all calendar events previously created by this user remain intact. All calendar events originally created by the deleted user will now be displayed as being created by a user named "Deleted User". Additionally, the time zone for these events will be changed to the default time zone of the Jira instance.
This ensures that no historical data is lost or incorrectly attributed, and the "Deleted User" label helps in identifying events linked to former users.