This sounds interesting but is really lacking details. Though... now I wonder what happened to singularity / midori.
https://www.infoq.com/presentations/csharp-systems-programmi...
Basically both projects achieved their goals, but Midori eventually was killed by management, even though they got an usable GUI desktop running with some core applications.
Some of their decisions influeced async/await design in C#, the AOT compilers to native code in WP 8.x and WP 10, some of the new features for C# 7 and others planned for future versions.
https://github.com/dotnet/corefxlab
https://github.com/dotnet/corefxlab/issues/952
As for scope M#/System C# style, I guess the door is still open for future C# versions.
Meanwhile You can try building it and play around with source.
edit: ok, found the project license (bsd) but you really should update those headers...