I think this benefits DirectX 12.
Apple saved OpenGL from extinction when it was chosen as the iOS 3D API, as the API never had a foothold on game consoles.
Apparently now they are done with it and with no plans on adopting Vulkan.
Why adopt Vulkan given their investment in Metal, to the point that they have moved their accelerated 2D stack to Metal.
What is the point to rewrite it again for Vulkan?
Even if they adopt Vulkan, most likely would be a layer on top of Metal.
As for being in the group, Sony is also and they don't use OpenGL on their consoles.