Amusingly I see this happen all the time in the information security domain. Two researchers coming out with the same results at basically the same time and they were isolated and doing the work independently. It happens in science and other areas so often. It’s an interesting phenomenon for sure. Maybe someone has named it and thought more about it. I just imagine we are all primed with roughly the same information and resources and these lovely little coincidences pop up from time to time, relatively often.
I found it amusing that this time, both the article submitter and the second person to do a similar hack are named Josh. Perhaps that's slightly less common.
Serendipity perhaps? As an aside, it's one of my favorite words. In my opinion it's a beautiful configuration of letters that's sounds lovely when saying it, and the meaning of it is equally wonderful. As a word, it makes me happy.