Streams Inventory Report doesn't class items as Orphaned though their Owner not in AAD

We have discovered an issue in that quite a few of our items are showing as non-Orphaned in the Inventory Report although through sampling we have have identified many where the Creator is either no longer in our AAD or their account is disabled (both use cases identified).

We believe this may be because of the way that the Migration Tool and Inventory Report work. It is stated that an item is orphaned if it has no Creator or Owner. In the use cases we identified there is usually an Owner identified who is still currently in our AAD so we assume this is why the item is not identified as Orphaned. However, these items are still named as per the absent Creator (not the current Owner) and we do not know whether the process identified in the migration documentation (which states that if an item is shared it will migrate to the Creator's OneDrive but be shared with any Owners) will  still be attempted if the Creator has been removed from our AAD and has no OneDrive account or where their account has been disabled. We are not sure what will happen in the use cases we identified - whether the object will error or whether a different process is planned for those use cases but has not been shared yet with us.

Has anyone else identified this same issue or discussed this with MS?