How is that even possible, surely you can email them and get new codes?
I'll be honest, I tried them anyway and they worked, so I didn't research this with as much indignant rage as I might have done.
The only other games I've had with extra content that wasn't on-disc are Heavy Rain and The Last of Us GOTY, and they both had limits. I'm not sure how long they were but I feel like they were longer. Looking it up, the codes were dated for a year to the day after the game's release (the deluxe edition was released at launch rather than later, which I didn't realise) but even then, one year seems a bit stingy. I'd be wary about purchasing a deluxe edition if I were you, at least.