I was expecting the 3600 and 3700X to lead the list, since they seem to be the best-value 6 and 8-core parts of the new lineup, but it looks like they are not in stock at Amazon, and only available from third-party sellers at marked up prices at the moment, which is likely why they are not in the top ten.
As for the point of the article, it's only logical that newly-released products should place well in a bestseller's list, so I'm not sure this is indicative of much. Ryzen processors have placed well in this list for quite a while already, so not much has changed.