Here is what they say is the "leak"

"How it leaks

WSL2 uses Hyper-V virtual networking and therein lies the problem. The Hyper-V Virtual Ethernet Adapter passes traffic to and from guests without letting the host’s firewall inspect the packets"

So they are complaining that the linux subsystem and distribution packets are not processed by the windows firewall. I don't know what to tell you, but the idea that the windows firewall should be in the mix on a fedora distro seems a bit rediculous?

You didn't reply to the article directly, you replied to a comment on the article - one that was making the exact point that you are repeating.

I thought they were saying microsoft needs to document this third party software behavior. Definitely the VPN folks should document this.