Samsung would be in constant contact with Corning and would be been shown the latest and greatest they were working on, for sure.
Samsung have already demonstrated that they will not hesitate to drown the market in mid range and low range phones, will can help empty out the stocks of old-grade gorilla glass production material, and thus Corning would not need to withhold their latest and greatest product from being used in one of their top customer's latest and greatest phones. There is no legitimate reason the Note7 wouldn't have GG5, even if hell did freeze over.