Even if they did, there is still the problem of boutique chips being last in line for the Foundry production priorities. Just as is still the case with 16nm chips first come the folks who financed ALL of the research involved eg, Apple, AMD, Cisco, Broadcom, et al.
For Global Foundrys, there is also the "by terms of contract" amount of their foundry capacity that IBM and AMD have first call on, dating back to when IBM and AMD spun off their foundry operations into what became Global Foundrys.
IBM and AMD have absolute first call on a certain amount of foundry capacity (they also have a REQUIREMENT to use a certain amount of capacity as a minimum) that GF can NOT avoid without incurring some rather large contractual penalties (I believe there is an "acts of god" provision in those contracts however).