The following is just my opinon on all this, but the way that I see it is that W4 represents industry priorities in the engine. In this example, the industry needs strong console support or cloud gaming and is willing to invest in it; or previously DirectX support. The Godot Foundation ensures that godot is able to focus on non-industry needs as well as community management. So they technically both contribute to the engine, but dont really overlap with each other cause they represent different groups who need to do different things with the same engine. That said - interop is needed as well because it is the same engine. ATM I trust juan and crew and the buracracy that is being built around godot to protect it and us while maintaining momentum.
Everything is locked down and filled with NDAs when it comes to console development. To access the xbox game development documentation - you need to sign an NDA (https://learn.microsoft.com/en-us/gaming/gdk/_content/gc/getstarted/gc-getstarted-toc). To access the SDK (https://www.microsoft.com/en-us/software-download/gdk) you need to be a “Registered Dev Center Partner” which requires a publisher, fee payment, and agreement (https://learn.microsoft.com/en-us/windows/apps/publish/partner-center/open-a-developer-account). BUT even more specifically section 3 of the public GDK license agreement (https://github.com/microsoft/GDK/blob/Main/LICENSE-EN-US.MD) gives an idea of what you are allowed to do with that SDK code once given access and you can only use the code for “internal” use and only make one copy for backup use. This isnt even getting into how using the GDK makes your app subject to the usage agreement (https://support.microsoft.com/en-us/windows/usage-rules-for-digital-goods-rules-83812b1f-1ecd-9a46-d3a7-ad1eadce49d1).