I e-mailed UD, asked how will mystery cuts redemptions work. Here is the reply. Reads like they don't even know?????
Regardless of the method of redemption, legendary cuts mystery redemptions will be unknown. Our database will be updated about 4 weeks following the shipment of the last redemption cardů which means that you will find out who you get when opening your package before we get that info!
Upper Deck Customer Service
Sports Cards: 800.873.7332