Actually...
I don't see why this is Facebook's problem. Like, at all. That's like arguing that a paper company is responsible for the Daily Mail printing bullshit on their product.
News should always be consumed from multiple sources and cross-referenced. Failing to do that is pretty much on the consumer's head, not the medium he found it on. If you can't tell the credibility difference between the NYT and Breitbart... well, that's an education system issue. For example, if I paste a fictional story about an alien invasion on FB, and someone is stupid enough to think that it's true, then it's not Facebook's fault for failing to flag it up as fiction. It's your fault for not being able to check other news sources over trusting a completely unknown dude on the internet suggesting Arkansas has been taken over by the Vogons.
This is what happens when your education system doesn't provide any critical thinking skills until halfway through university. Which more or less all Western education systems have been designed around for decades - there were tight oligopolies controlling the dissemination of news, most of whom had comfortable by subservient relationships with the state (even when they were nominally hostile to it), so you just didn't have avenues for fake news to go global. Meanwhile, you only wanted, say, 20% of the population to be involved in managerial tasks that required the ability to critically engage with data; everyone else was bound for the factory floor or mostly just needed to know not to stand under the steam hammer while it was in motion. So it was fine - and actually desirable - for 80% of the population to have no serious critical thinking skills whatsoever, as otherwise they might start questioning official narratives - like 'We're always the good guys, even when we're dropping napalm on peasant villages'.
The internet (along with aggressively partisan media outlets that overtly challenge mainstream narratives for political ends, like Fox News) is slowly breaking that shit down. Iraq 2 was when it really started to kick off, as the official narrative (Sadam is connected to 9/11 and has WMDs) simply wasn't convincing to those who did have critical thinking skills, and they could circumvent the controlled official channels to talk about it rather than being shut out in the cold. Every major newspaper supported the war at the start. It was bloggers who were saying it didn't add up. That caused a collapse of trust in the 'official' narrative forming channels (the newspapers etc), but people didn't suddenly develop the ability to critically analyse information themselves - they disliked the media because it had proven to be lying AFTER the event, not because they didn't find the arguments convincing while they were being made. So now they don't trust the Lying New York Times, but they don't have the skills needed to determine whether Infowars.com is a pile of fictional dogshit until some idiot goes and shoots up a pizza parlour to prove it wrong.
The answer to this is not 'we must re-empower the gatekeepers of information', because the gatekeepers are inevitably corrupt, whether they're Facebook, or the NYT, or the Washington Post, or the Guardian. It's to make sure people can actually tell if an argument is actually convincing or not. Which is what Facebook's ten points are actually trying to do - point out a basic university-level critical thinking process which you really need to understand to survive in an information-rich environment.
So no, I don't want Facebook to suddenly declare itself the editor in chief of the internet, and yes, it should be down to the user to check.