For sure, they should be able to at least make the redactions and make more of the files open to the public.
I think that Omidyar sought to gain "cool" points / street cred for creating the Intercept that promotes itself as "adversarial journalism". In doing so, he gains the credibility as a progressive forward thinking organization but the real goal was to capture and control the archive.

Yeah, there's certainly a need for a blockchain archival tool, it's something I'm very interested in and would like to help create one if possible.