Even the CBC is making an article about it! π
I saw someone speculate elsewhere that it could be that some high-profile subreddits were hard-coded for the front page, and them going private could have crashed the system. That would be a bad implementation, but is a reasonable explanation for why everything stopped working.
Im surprised that the big ticket subreddits, of which there are only a handful, are yet publicly moderated. Tbh I do forsee them changing ownership of these 20 odd subreddits and getting to a point where your average joe cant tell a blackout is occuring. Whether they can maintain the standards is up for debate however.