The current implementation does show items that aren't visible on the board but it's too subtle. Unmapped statuses are shown with an interrobang, deployed fix-versions are shown with a checkmark, items no longer in a sprint are shown by the absence of an active sprint. All of these should be shown in a consistent way to draw attention to the fact that nobody is seeing them and therefore, we've forgotten about them.
The current implementation does show items that aren't visible on the board but it's too subtle. Unmapped statuses are shown with an interrobang, deployed fix-versions are shown with a checkmark, items no longer in a sprint are shown by the absence of an active sprint. All of these should be shown in a consistent way to draw attention to the fact that nobody is seeing them and therefore, we've forgotten about them.