Addon set as unavailable still returned by IAP.GetProductsBySKU

We have some addons that we use for testing that we no longer use. The Meta Dashboard doesn't allow us to remove them, only allows us to set them as unavailable. But when we can IAP.GetProductsBySKU, the items that are set to unavailable are still listed, and the products do not have any property mentioning their state so that we can check if they are unavailable.

Am I missing something, or what's the point of this option?