With WSL they are absolutely at the "extend" step.

Notably, there are some passthrough APIs to extend the captive Linux with Windows features.

It's somewhat hard to find, so lest anyone thinks I'm making it up, here are two things I have heard of - DirectX passthrough and (probably related) DirectML passthrough

https://devblogs.microsoft.com/directx/directx-heart-linux/

https://learn.microsoft.com/en-us/windows/ai/directml/pytorc...

Ah, I didn't know about that. I stand corrected, WSL is at the "extend" stage.