Actually, I was asking the second one: about having MetalGL available on android/win/linux.
I believe that developers need more portable mid-ware solutions, and OpenGL ES is a good choice.
On Windows we can use Google’s ANGLE to run GL-ES on top of DX. Kings (makers of Candy Crush) uses ANGLE for their ports to Windows mobile.
I guess MetalGL, using METAL on IOS/OSX, or Vulkan on other platforms would be great for portability, as well high performance.