It's difficult to pull out particular factors from the election, and I doubt that we'll ever have a truly objective yes or no to this question. Donald Trump won. He used social media in innovative ways. Does the latter explain the former? Who knows? It's not like votes come with an explanation.
Facebook is an interesting example. The quote mentions "...outright lies peddled as objective truth by shady actors both inside the US and abroad." But the interesting part is that the people outside the US were apparently doing it purely for profit. Apparently the ad revenue from fake news articles posted on Facebook was enough to make a decent income in Macedonia.
It's a fascinating intersection of Trump's celebrity, Clinton's unpopularity, and right wing hunger for news. And it doesn't even require actual malfeasance. It's possible that it arose on its own, although it is also possible that someone like Roger Stone (Trump's version of Bob Creamer) started it. Regardless, it seems to have spread into a cottage industry.
Twitter creates soundbite length posts. As a result, when the media would cover something that he posted, they tended to either quote exactly or show the actual tweet. The point being that his tweets were reaching even people who weren't "tech savvy".
The fundamental problem with both Twitter and Facebook is that they tend to be read and followed by supporters. But campaigns only need to reach supporters to encourage them to vote. The harder task is reaching potential supporters. Social media doesn't help as much with that, although retweets and likes can help somewhat.
Traditional media still reaches a number of potential Trump voters. The restricted nature of Twitter allowed Trump to talk through traditional news. Of course, his rally speeches also generated free media mentions, but Twitter has the advantage of more control. They can pick any section of an hour long rally to quote, but it's hard to excerpt Twitter.
Trump also received support from other media. For example, radio stars like Rush Limbaugh and local versions endorsed him. Fox News may not have endorsed him, but their editorial comments were mostly in favor. There has been some speculation that conservatives in places like Wisconsin, Michigan, and Pennsylvania may have been encouraged to vote by negative news about Clinton and positive coverage of Trump. It doesn't take much tech savvy to listen to the radio while in the car.
Comparing this year to 2012
Trump got around the same number of votes as Mitt Romney. The real difference in this election was that Hillary Clinton received about five million fewer votes than Barack Obama. As such, it's not established that anything Trump did improved over Romney, except picking an easier opponent. Since there were two million or so more votes in this election than 2012, the normal expectation would have been that he should have beat Romney by a million votes or so. Whatever he did had the net effect of losing him a million votes rather than gaining.
Now, it could be that Trump lost millions of votes by being, well, Trump. And then gained back one fewer millions through social media. He did much worse among more educated whites and better among working class people of all races but especially whites. That's a reasonable hypothesis but ultimately uncheckable.
People asserted that Obama's success was caused by his data driven campaigns. He transferred that apparatus to Clinton, but it didn't work the same way for her. Is the theory disproven? Obama was also known for the high quality of his social media. But Clinton wasn't able to copy his success, even though she had many of the same staff.
It's possible that the better (or less worse) candidate won. Would Ted Cruz, Marco Rubio, or John Kasich have beaten Clinton? Would Bernie Sanders, Martin O'Malley, or Jim Webb have beaten Trump? We'll never know.
Note: by better/worse candidate, I'm referring purely to electability rather than ability to be president. We'll never know objectively who would have made a better president (although many have their suspicions). And we won't know how Trump will do until he actually has a chance to do something.