In Pages > Basic Editing, the list that is generated for "These products have not been assigned to a page" includes products that have been assiged, as subproducts, to products that have been assigned to a page.
I have used this list, in previous versions, to identify unpublished products prior to the 8.1 upgrade and don't recall all the subproducts being listed.
Is this a change between 8.1 and previous versions?