Good Lord, will they ever realize the primary wasn't rigged? Hillary won the popular vote by 13 points and came 100 delegates from winning an outright majority of delegates, to where those evil hated superdelegates would be completely irrelevant.
They aren't talking about superdelegates or the vote count, they're saying the DNC wasn't neutral during the primaries. Tom Perez admitted as much:
"We heard loudly and clearly yesterday from Bernie supporters that the process was rigged and it was. And you’ve got to be honest about it. That’s why we need a chair who is transparent."
https://www.nbcnews.com/politics/politics-news/race-dnc-chair-tom-perez-pledges-woo-back-red-rural-n718536