My perspective is that it's there so it shows up on search results for "installing Linux" and recommends WSL over bare metal. At least that's how I understand the wording.
True. Dont trust that company. They may invest 1% of their money into WSL now, but its for making the "Linux" experience so good there literally is no reason for many anymore, to really switch.
Indeed, it's to contain the "Linuxification" of the developer community.
Before WSL, any developer dealing with backend development almost had to install Linux to have a vaguely decent development environment to align with what they get to use on the servers. While they were dragged into that world by their requirements, they may find that the packaging and window management is actually pretty cool. There reluctance to venture out of the Windows world transforms into acceptance and perhaps even liking it.
Now with WSL, those Windows desktop users say "I just need to click a distribution in the Microsoft Store and I'm golden and don't have to deal with that scary Linux world I don't know yet.".
I've repeatedly have people notice I'm running a Linux desktop when I'm presenting and off hand say "you know you can just run Linux under Windows, you don't have to endure Linux anymore". They seem to think I'm absurd for actually preferring Linux when I can get away with it.