If I'm interpreting that correctly they're using an IL2CPP compilation system that hooks into Roslyn and not using .NET Core's AOT technology. It's possible to ship C# on consoles, obviously, because Unity already does it with their own IL2CPP backend that's stuck on the old .NET versions. My point is that CoreCLR can't be used because of console certification requirements. I certainly wasn't commenting on C# as language for games. I think C# is, as of late, becoming a very powerful language for games with all the Span and similar tools to minimize GC pressure.