Here we are, more than 3 years after that article was written, and we are no closer to the NFL, NCAA, or even High School ball having any sort of mandate for helmets.
And it's not like there aren't other helmets that could be used. In fact, a quick search found that SCHUTT makes a helmet they claim that is even safer than the Riddell Revolution mentioned in the article and it is the same size as the "traditional" helmets players supposedly like.
So, from what I can find, there are actually 4 different "anti-concussion" helmets on the Market. 2 are from Riddell, one from Schutt and one from Xenith. 2 are the "large stand-off helmet" style (The Riddell Revolution and the Xenith) and 2 are the traditional style helmets (Schutt and Riddell VSR-4).
That being said, I don't know if SCHUTT is on the NFL preferred vendors list. If they aren't, then the NFL has some explaining to do.