According to a couple of Users in General Discussion thread the AMD Store was selling the new GPUs directly from AMD but when supplies got exhausted the AMD Store now refers to a 3rd party Retailer to get the new GPUs and processors.
In the past, at AMD Store, when you clicked on "Direct BUY" it went to an official AMD Website to purchase the new processors or GPUs from AMD, but now if you click on the "Direct BUY" it goes to a AMD webpage showing where you can purchase those hardware at 3rd party Retailers/vendors.
NOTE: Just guessing but possibly when AMD restocks with more new GPUs and Processors you might be able to again purchase directly from AMD Store.
