The thing is, I don’t think a guide is really needed to install Linux. Most of it is pretty straight-forward. (The only tricky bit that comes to mind is making the USB that you’ve put your distro on bootable. That probably isn’t obvious; and it might not be obvious how to get your computer to boot from a USB anyway if you’ve never done it before.)
Anyway, the way I see it, Microsoft’s guide is more about how you can use Linux while still having Windows. If someone is searching for “how do I install Linux?” Microsoft would obviously prefer the answer to involve something that preserves Windows. First preference: WSL, second preference: Virtual Machine, third preference: dual-boot. And after that, you’re on your own.