Some years ago the USPCC changed up their policies in order to be able to fight copyright infringement more effectively. To that end, they no longer allow designs that alter their copyrighted images to be printed. That means nothing that changes the Ace of Spades, Jokers, or back design (other than coloration) can be printed any more.
That means that decks like the Red and Blue Bicycle Gaff deck, The Ultra Gaff, and other designs based on the Bicycle design cannot be printed any more. As they sell out, they are being discontinued simply because we cannot print them any more.