getting a local account is simple.
Windows Pro > Work or School Account > Join a Domain instead > Set password & recovery questions
The one component here that is not present on most machines straight from the manufacturer is the presence of the Pro version. The home version of windows requires the account with increasingly limited alternatives.
As the author mentions in TFA, she's on the Arch staff as a package maintainer. I don't think there was a technical obstacle around the windows setup process.
https://archlinux.org/people/package-maintainers/#josie
I wonder. I sort of accidentally discovered that Rufus could edit my arm64 windows 11 install media without problem - adding a local account and bypassing the need for domain login (just as it does for amd64).
This isn't a new trick - just the regular approach to editing windows install media.
Simple™. Easy™.