I was under the impression all the big modern consoles were using customized AMD GPUs. For example, according to the PS4's Wikipedia entry [0], its GPU is a "Semi-custom AMD GCN Radeon (integrated into APU)". Are those customizations made by AMD for Sony, instead of licensing the technology?
I found an article claiming Intel is licensing AMD GPU technology [1]. If that's the case, would it be surprising to see Apple do the same?
Yes, those customizations are made by AMD. They aren't even very custom, fail0verflow have managed to run a lightly modified linux kernel with the open-source AMD drivers on PS4 hardware with full graphics acceleration[0].
[0] https://fail0verflow.com/blog/2016/console-hacking-2016-post...