That is not how any of this works. CryTek sold off their rights to Amazon with the creation of LumberYard. CryTek cant argue anything about LumberYard code.
Doesn't matter - as it was explained to me, the onus will effectively be on CIG to demonstrate why code that is identical to code from CryEngine should be retained in the event that they are order to remove it. That the code came from a different source but is otherwise identical won't be a solution unless they can prove it. What is fun is that LumberYard is based on CryEngine so there is bound to be a lot of crossover. A lawyer would be able to point out the loopholes and the details, but essentially CIG cannot claim to be removing CryEngine and then keep CryEngine code in place with the claim that it derived from LumberYard instead.