It wouldn't be antitrust if YOU are the manufacturer. Amazon does this for some products already, particularly their own. They don't let 3rd parties list AmazonBasics products or Kindles.
Other retailers do this all the time. In fact, that used to be the status quo—signing an exclusive with a retailer.
Other retailers do this all the time. In fact, that used to be the status quo—signing an exclusive with a retailer.