I'm using a computer without sound, so I didn't watch this, but based on the headline, I don't think opinion is 'fake news'. It's certainly arguable whether multiculturalism is beneficial to Germany, so it's not the equivalent of a made-up story.
There are hundreds of thousands of people who believe that an FBI agent was murdered because he leaked Hillary's emails, or that Obama signed a bill outlawing the Pledge of Allegiance, etc., etc. These stories aren't just disagreeable interpretations of fact, or carefully and misleadingly card-stacked arguments--they're deliberate fabrications created out of whole cloth, either for sport, political advantage, or profit.
The 'fake news' phenomena is important because there's plenty to discuss without the complication of introducing deliberate falsehoods into the mix. If we're all starting with the same facts, there's a lot of discussion available as to the benefits and detriments of multiculturalism, and how it can be managed to maximize the former and minimize the latter.
I don't think Fox News is 'fake news', in the new and strictest sense. The 'Faux News' epithet (which I don't use) doesn't mean that they're spreading made-up stories, but that in some people's eyes they're not a real news station.
The 'fake news' term is being co-opted into meaninglessness. That's partly deliberate on the part of people who benefit politically from the spread of fake news stories and want to draw attention away from it by using it for nearly everything. As has been pointed out, the true practitioners of this dark art concentrate on pro-Trump stories because that's who falls for them. So people with a stronger sense of partisanship than honesty have a stake in letting the fake stories continue and creating a diversion by pointing at legitimate stories and contrary opinion and saying, "Hey, look here! This is fake, too!"
For the record, there's a lot of stupid opinion and poor reporting out there, but it's not fake news to me.
If we use it to describe interpretations of events that we might not find amenable (like your clip, perhaps), or to describe truthful and accurate reporting about actual events that we wish didn't happen (as in DDickerson using the term to describe the media's accurate reporting of CIA findings on Russia's involvement in the election), we distract from our one area of agreement--that it's better if our opinions, even if different, are at least based on things that weren't made up.