Github complies with the DMCA, recently famously through the DMCA takedown of youtube-dl. The writer, Joey Hess (a relatively well-known OSS programmer, moreutils, for instance), is choosing to interpret this as their banning any repo that hosts the commit hash for youtube-dl (which they banned).
So he is jokingly showing you a way to create a Github poison pill. The joke is that if you include this 'illegal' hash you subject the repo to being DMCA'd out (not really, but it's sort of an 'imagine if'). Which means his repo is now unpublishable on Github (for long anyway).
It's kind of hacker humour in the sort of vein that you'd expect from an old-schooler like him. You sort of have to get the joke to get the joke.
So he is jokingly showing you a way to create a Github poison pill. The joke is that if you include this 'illegal' hash you subject the repo to being DMCA'd out (not really, but it's sort of an 'imagine if'). Which means his repo is now unpublishable on Github (for long anyway).
It's kind of hacker humour in the sort of vein that you'd expect from an old-schooler like him. You sort of have to get the joke to get the joke.