In your mind, company that as a contract with a fab is not fabless? Do you think AMD can just stop ordering from TSMC today and call it a day?

AMD was fine with having GloFo as a fab until 20nm process. They were already behind, but not terribly.

AMD even used TSMC for their CPUs and GPUs before Zen. Ontario was fabbed at TSMC in 2011.

Point is AMD as free to shop around. Only in 2016 the agreement was amended that GloFo would be preferred for 14nm and 7nm, but since they decided not to work on 7nm, it freed up AMD.