It says to work..
in partnership with Apple" to "define and shape the future of OpenGL both for computer platforms as well as next generation consumer electronics devices."
All companies have guys who work directly with the consortium and other people in the consortium... that is how standards work.
MS works with Nvidia, AMD and others on future DX versions because only working together can you actually come up with a list of features everyone wants or needs and provides a starting point for making the next version of an API. There will be people within Nvidia whose primary job is working with MS, working with Apple, working with Intel, working with Khronos Group(who do openGL/Vulkan). In fact I believe the current president of Khronos is an Nvidia employee.. or maybe a recent president of it.
This is how the industry works, guys from each company are designated to work on APIs, individuals or groups are designated to work with various different companies. You can't just make DX13 in isolation, launch it and expect Nvidia/AMD and everyone else to have support for it in hardware within 3 years. It's an ongoing collaboration between many companies, in the case of Khronos, Apple/Nvidia have always been the bigger players.
Then have a look at how Mantle used very similar commands to D3D, precisely for compatibility reasons in terms of having devs be able to pick it up easily. Then DX12 apparently uses nearly word for word identical commands to Mantle, and Vulkan also very similar.
Metal is no different in that it shares a hell of a lot with openCL and openGL, enabling similar functionality but at a lower level. Basically it's a fairly standard job posting and Nvidia/AMD/Intel/Apple all have guys who work with various other companies when it comes to working towards industry standards. If you don't standards never move forward or you individually will never have hardware that supports industry standards.
Nothing about the job listing suggests a specific future product (though that can absolutely happen), it's completely standard for companies to work together on APIs(and any standards) where having everyone on roughly the right track together makes a hell of a lot of sense. The job listing is about shaping the future of APIs... which themselves will be used in future computers/platforms, not about future computers/platforms themselves.
