Unreleased product and unredeemed singles are different issues completely! UD makes no bones about putting an expiry on their redemption, at which point they go into replacement stock - hey, something has to be replacement stock. Putting unreleased cards into the market as replacements that never even had the chance to see the light of day through normal avenues is unacceptable, IMO.
I'm not sure if Q said it here or on Beckett but I would expect to see UD do a box giveaway promo at the Fall Expo (crack some product, get some free product) before they start using it as replacement stock.
