I have tried that for the past few months and yet to be able to get the code returned. I don't know if this is a recent change since last year but several others have stated same to me; they can only inform you whether your vehicle has been given a production date, and the date if it was.
Having said that, they speak directly with BG every time, but I dont know if that is any different than NOMS. I have never requested that specifically...will try.