They already treat Trash/Bin as a special concept internally. They have since launch. You cannot have 'Trash' and other tags/labels, like 'Inbox' set at the sam

They already treat Trash/Bin as a special concept internally. They have since launch. You cannot have 'Trash' and other tags/labels, like 'Inbox' set at the same time, for instance. So it might be a disgusting hack, but it's been whatever it is since launch, although incompletely.