I wouldn't be surprised if Apple is coming up with a plan to remove Intel / AMD / Nvidia chips entirely from its products. Previous jumps from Motorola 68000 -> PowerPC -> Intel already shows they are not afraid to do so. There's been a lot of rumor in regards to entry level iMacs / MacBooks going with ARM chips, and now there's hints that they're building additional GPU development teams. Yeah, it could be for just the mobile lineup, but also keep in mind that Apple lags behind in updates to the included OpenGL build, has no plans for Vulkan, and only talks about their Metal API on macOS, something that originated on iOS. Apple claims Nvidia is also slower with OpenCL routines, which is why they favor AMD, for now.