The message text says: "Removal of assignment to $2".
The qqq page at https://translatewiki.net/w/i.php?title=MediaWiki:Notification-bs-pageassignments-assignment-change-remove-subject/qqq states: "$2 - Name of the user, that removed the assignment of the user". This cannot be right.
Please adjust the qqq, or maybe the message should refer to $3 instead of $2.