they know nvidias very slowly dying and playing some damage control, they're trying to be like apple using an open source system then making a closed ecosystem out of it.

Chance they opened sourced it because people pretty much figured it out by reverse engineering

Does Microsoft have newer code that's still closed source, is this old code ?

Could they open source an old inefficient method while keeping the up to date efficient methods to themselves

Maybe native directx on non-windows hosts????