Two things should be noted, one is that "SJW" is not so easily defined, it probably should not be used blanketly for all people concerned with simple common social justice. There are a lot of ignorant simplistically thinking "lefties" who spout nonsense and outrage because it seems trendy or cool. I do not think that crowd could be characterized as SJW and yet I suspect they are the ones your article really is referring to. (I'd love to cite data on this, but no research exists AFAIK on such current sociology.)
Another is that there is good and bad cultural appropriation, and a lot of the insane lefties and lunatic right wingnuts alike tend to confuse the good and bad and cherry pick the worst appropriations to support their case. I think the truth is that social media amplifies the bad. That's just a simple consequence of how social media rankings are determined algorithmically, and the whole click baiting culture. I think here on Steem there are some built-in measures to avoid such popular eye-candy ranking unintended consequences of Likes and Up-votes. But it still is not going to be perfect. Any loosely monitored mostly algorithmically ranked system will get gamed eventually. So I suspect you don't have to worry a heck of a lot about any trends in cultural appropriation outrage visible in social media statistics. It is what it is, the worst in us all is amped by social media. What we need to worry more about is stifling of the good in any culture, period, as well as universally abhorrent harm permitted by traditional culture of all kinds under the disingenuous guise of cultural preservation --- usually such abominations are merely the old power structures trying to preserve their grip over the unfortunate people under their fold.

And I think you are deluded in your final comments: "If the push to end war received one tenth of the coverage that the push to end perceived cultural appropriation gets, there could be peace by the end of the month." That is way off. base man, and a bit laughable. Although I appreciate the sentiment. There is no really big money or big "push" behind the anti-cultural appropriations movement, it is more of a trending meme I think, it will pass. To seriously end widespread war requires sucking money out of arms deals and weapons manufacturing, getting rid of corruption in the military-industrial-government neoliberal complex which wants war because of the profits they accrue from war. And it requires true collective security arrangements, not the f*d up collective security pact of NATO. The world needs a proper global collective security arrangement with a slogan something like: "An attack on any democratically or justly governed elected nation is an attack against us all"

Trouble for peace is that hold-outs like the USA and Israel, among others, will never sign such a security pact because they are totally insecure about being judged "unjustly governed!". Not that anyone will ever dare attack the USA, but the USA conservatives still are so pathetically insecure about the way they are perceived internationally (and for good reason!). That's why the issue of anti cultural appropriations is insignificant for world peace. There are much bigger germs of war that need inoculation. We need firstly a total reorganization of systems of government to get them free form corruption and donor and lobbyist influences, and acting more justly and reflecting the voice of their citizens through mechanisms like true proportional representation, and even more radically by eliminating political parties (which I think are anachronisms of a pre-Internet age where politicians had to legitimately form collectives to get brand recognition) and allowing every candidate for office to stand as independents.