The mechanism would be same as the current Facebook’s quality survey. As a result, users would be asked about the credibility and authenticity of the news sources and if they trust it.
There is plenty of sensationalism and bogus links in the news feed. Ultimately, the news gets shared across and it further creates more chaos. According to Mark Zuckerberg, his company is keen to screen out all such fake news channels from the internet to ultimately encourage authenticity and realism.