I'm curious about that, too. I'm betting they are serious and just didn't get that it was a joke. As it stands I'm not quite sure I get the joke either, but it is kind of funny how useless an organization scheme this is since all the repos are unrelated and it's highly unlikely any one person would be looking for multiple element-named projects.
I think it'd be even funnier if the repos it links to weren't even named after elements, but just had names resembling the abbreviations or something. But then again, it would be hard to find some more useless grouping criterion than being named after an element... I wonder if it's actually worse than random :)
It's not an organization scheme in any practical sense. It's just a way of looking at all the repos named after elements and seeing which ones are still up for grabs, because naming things is hard so let's pick an element and name it that! But more than that, it's just a personal exercise and publishing something without getting caught up on weeks of perfecting it.
I think it'd be even funnier if the repos it links to weren't even named after elements, but just had names resembling the abbreviations or something. But then again, it would be hard to find some more useless grouping criterion than being named after an element... I wonder if it's actually worse than random :)