The 256GB and 512GB Steam Decks come with some digital rewards, such as an exclusive steam profile customization bundle and a unique virtual keyboard (keyboard is 512GB only). Previously these rewards were not available to refurbished deck buyers, but Valve plans to change that and make these rewards available regardless of whether you buy new or refurbished.
I bought mine refurbished from Valve but the rewards were already redeemed. Guess I need to contact support