Yup, I had read the article the other way around. Designing their own ARM core didn't make much sense to me. Using someone else's does.

Considering AMD is now a fabless chip design shop, not doing any design work doesn't make sense to me. What is their value add? They may as well have ordered a shipment of completed processors from Nvidia.

In this case, the value add is the processor interconnect fabric. In other cases, it will be their GPU.