I feel like the 8-K brings some official feeling to the news for the company.
I don't know if you remember this, but when I posted the delisting PR - and the company's website said it was delisting as well - a lot of people doubted it until the 8-K came out and said the exact same thing.
Yes, you and I and others actively watching the stock know what happened, but the news probably didn't get out as much as we would have liked.
The 8-K filing gives it legitimacy and many more people are willing to trust an SEC filing over a PR.
Of course, the CAFC is an official source as well, but in this case, it just gives the information in the 8-K even more credibility.