lol.
That's called hype.
I've never spoken to a single person who ranks websites on Google say to me. "You know.. I've noticed that backlinks just don't work anymore, especially PBNs. Facebook and twitter on the other hand have gotten me ranked for dozens of competitive niches.."
Not a single one.
Stop reading crappy whitehat matt-cutts-approved blogs and try to rank some sites and you'll see what the reality really is.
Here's an example of why "trends" are complete nonsense. Remember, SEO blogs are run by marketers who are trying to get readers. They're just online newspapers. Their goal is to make money, not help the world get good at SEO.
http://www.toprankblog.com/2011/03/future-trends-search-social-media-marketing/
So back in march 2011 the new trend is social ranking.
But, yes, 2015 trend is now social ranking

Or maybe it's just more blogs trying to make money and create noteworthy news.