Sorry for the delayed response, life's hectic.
Its really no big deal. It seems like Brazile got a lot of the details wrong (and its far less underhanded than initially appeared...and appears to even be a case of Clinton, to some extent, saving a bankrupt DNC from itself).
To the extent that Sanders was unfairly disadvantaged, that's nonsense. There is no fairness component. The DNC is a private organization. They could opt to select a candidate by drawing names out of a hat. I've said it before, I'll say it again, it would be dereliction of duty for the DNC Chair to stand idly by as a non-Democrat pursues the Democratic nomination. I hope that if Sanders runs in 2020, Perez takes steps to block him simply because he is not a Democrat. If anyone should be pissed about all of this, it is O'Malley and Webb.
As to how it affects things moving forward, I'm not sure.
Sherrod Brown is the secret weapon that the left refuses to use. This guy should be the face of the leftist movement. He has a better temperament than Sanders, is more likeable than Warren, and is able to make leftist policies attractive to blue collar, white men (Trump's base). He should've been Clinton's running mate.
That said, he is facing a very tough re-election bid next year. And while early polling is not terribly reliable, he seems to be down considerably when polled against the presumptive Republican nominee Josh Mandel (whom Brown beat in 2012).
Brown might survive. If Virginia and New Jersey taught us anything, its that a blue wave is coming, and that might save Brown's Senate seat. If he does survive, I expect to start hearing his name floated quite a bit as a potential 2020 candidate (though I don't think he'll run if Biden does, and Biden is going to run).