The only reason Nvidia, or any of their partners, would do so, is if they would have more stock than they could sell on launch date. Judging by the current hype-train, the demand will far outweigh the supply. How would it be beneficial for Nvidia to sell their GPUs at a lower margin (for them) than if they were to sell them straight to the customer, if they're sure they can sell all the stock they have easily.
Massdrop makes sense for "mature" technology, where the demand is at or below the supply level. It does not make sense when demand outweighs the possible supply.
TL,DR: This won't happen for at least a few months.