I imagine it would be the same situation. I am not sure what the purpose of this presentation was anyway, Costco was never in any danger from Amazon. They are in two completely different markets.
The cost of energy and labor to deliver big, heavy goods to an individual's house is obviously more than the cost for individuals to go to a giant store and get it themselves.
If Amazon had opened a store like Costco selling bulk goods, then it might have made sense.