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.
Makes sense. I bought one secondhand and still got the digital goodies.
If you buy it secondhand from anywhere but valve, it just depends if the previous owner claimed the digital goodies or not .