In /settings/panel/emailpreferences/ for "Maniphest Tasks" I have the following settings for one of my accounts:

⚫ Email - A task's status changes.
⚫ Email - A task's owner changes.
⚫ Email - A task's priority changes.
⚪ Ignore - A task's subscribers change.
⚫ Email - A task's associated projects change.
⚪ Ignore - One of the tasks a task is blocked by changes status.
◐ Notify - A task is moved between columns on a workboard.
⚫ Email - Someone comments on a task.
⚪ Ignore - Other task activity not listed above occurs.

I consider merging a task a status change (as it's not "Open" anymore but "Closed, Duplicate").

But when someone merges a task as a duplicate into another ticket I do not receive an email notification.

To me that is unexpected.