To answer your question directly, no I don't think so (perhaps some updated theories, but nothing concrete).
But the article does cover more than just the incident, I found the whole thing fairly interesting.
Beyond the passing knowledge I have from growing up in Chicago-land around the time and the Wikipedia article on the subject, I thought it contextualized the FCC policies around the time of the incident and how the hack worked (from a high level). It also pointed out other signal intrusions from the same period and the FCC/FBI's methods to track down the perpetrators.
If you haven't read the reddit thread from within the last year then it certainly has a great amount of new information. In fact, I thought the reddit theory was a more compelling story than this article
great article. One correction, however: They say one "suspect" was in "nearby" Bloomington, Indiana but Bloomington isn't really near Chicago. It is in Southern Indiana, about 4 hours away from Chicago and to get to Chicago you have to go through Indianapolis, so if someone from Bloomington were to do something like this it seems much more likely they would do it in Indianapolis or even Louisville or Cincinnati which are both closer than Chicago.
[1]: http://en.wikipedia.org/wiki/Max_Headroom_broadcast_signal_i...
[2]: http://www.reddit.com/r/IAmA/comments/eeb6e