As far as I'm aware, every System76 laptop is a rebadged OEM laptop with an opinionated set of expansion components that they've effectively certified as functional in Pop!_OS by ensuring good driver and DWM compatibility. I think the OEM is Sager, but I'm not confident on that, or if that's uniform. Anywho, because of this, it should be reasonably possible to source replacement components upstream.
Yep, Sager/Clevo. Clevo L141AU has the same specs (2.5 lbs, 14 hours claimed battery life, 65W barrel charger, same keyboard layout, i7-1355U option). The case looks close, maybe identical, to the photos in the article. https://laptopwithlinux.com/product/clevo-l141au/
EDIT: Customized the Laptop with Linux Clevo to the same exact specs as the review unit and got a total price of $1,507, so about the same, give or take $30.