Actually, I'd heard that it was under consideration to bring the Cupid Back into the regular rotation again as a "standard" deck, an alternative to the Rider Back for consumers. I couldn't tell you what's in the boxes, but it doesn't matter, since whether it's filled with Cupid Backs or Rider Backs, this was STILL a test concept that was never brought to retail in the end, making it the rare deck that it is. In essence, it's a prototype that was scrubbed before reaching production.
It could be filled with Cracker Jacks; wouldn't matter, still a rare prototype...