Author here. Thanks for posting this. This is something I wanted to continue. The plan is still discussing NetBSD source code, as much as I can. Reading NetBSD code is a great way to learn operating systems! :-)
Few years ago there was an similar thing but with OpenBSD code. There is a IRC channel on Freenode who a group of people go through OpenBSD code like "doas" and stuff.
I follow your future articles :)
The daily started in June 2017 we kept up doing it daily for 42 days straight. In total there were 47 code reads.