It’s true that we are never going to see first-party support for Linux from Apple. That kind of sucks, and it would be much better for everyone if they had a more open and documented approach to this new platform. But it does at least have explicit support for booting third-party operating systems, and the attitude of the team behind the project is clearly not “hack together a prototype and we are done”.
I guess the point is that it’s not black and white, and there’s a large spectrum between “first-party support” and “unsupported hack”.