That’s a worse situation then because Amazon would then be intentionally withholding data in counterfeiting investigations.

It wouldn't surprise me. Amazon knows where every item is in its FC and knows the motions of every item's placement, from the grand scheme of things.

It's not that hard to then track back from an order exactly what bin or tote or shelf the item was pulled from, then look at what shipment(s) that bin's items came from to figure out what supplier it came from.

They know the counterfeit goods came in and were stowed to bin XYZ and they know that someone pulled from XYZ...