Yeah, but if you read the instructions from the link Jason provided, it says 15-60 minutes max for the problem to resolve itself. I can't possibly imagine any fading or discoloration occuring that quickly to the cardback or the plastic itself. It might be enough to trigger discoloration in the plastic, but that's not instantaneous either. And if you cover the cardback as the instructions indicate you aren't going to get anything happening regardless to that part of the unit, so the only concern is the bubble itself.
I'm sure you could resolve the "mold" issue, snap a pic, run the auction, ship and deliver the item and receive good feedback well before any sort of discoloration started, if it even ever did, given the extremely limited time of exposure to the sun.