If you go into the GitHub of any of the forks, and check the contribution page, you will see this data is not correct. Probably all my commits are into this "unknown", since I push with @gmail.com account without being part of any organization for most of the time.
This is likely some partial data of some specific fork or alike.
The LWN article is examining the 976 commits made after the 7.0.0 release. I don't think you had any commits during that time?
As is typical for software projects, early authors will be disproportionately represented in revision histories. I am still the #4 contributor to the Anaconda installer [1] originally used by Red Hat Linux, then RHEL, then Fedora, and others, despite not contributing to the code base for two decades.
This is likely some partial data of some specific fork or alike.