The proper legal resolution would be refunding the customer and then settle it between Amazon and the author that didn't have the rights to sell what they sold. If I buy some food at the grocery store and there's a recall due to for example contamination, I can go back to the store and get a refund. I can even go to any store selling the same item without an invoice and get a refund (for their list price I think). This is at least the deal in Denmark. This should be the same if something was sold with a missing license or improper license (if it is sold as a product but the license the seller has expires and is not renewed)

Conveying something to someone in perpetuity (i.e. "selling" it to them) when you don't have the right to do so is fraud. Just because Amazon or whoever's right to continue offering the thing ended doesn't mean their customers' property rights somehow end with it.

It's exactly as absurd as a car dealer stealing back all the cars they previously sold just because they ended their agreement with the manufacturer.

There is absolutely no sane world in which stealing your customers' property could ever be the "only legal resolution!"

Agreed, licensing for anything like that in game should be required to be permanent. Only exception I can possibly think of is live service games where the content cycles out of availability.