I read that and was prepared to have my mind blown. Not really impressed, though. That article says this:

And you can literally say anything about North Korea, the most absurd thing you could imagine, and people would believe it.

That links to this article, which says:

The country has been in the news of late, as ongoing negotiations between the Trump and Kim Jong-un administrations appear to have soured. The chief casualty of this diplomatic failure, the New York Times (5/31/19) breathlessly reported, was Kim Jong-un’s negotiating team, with the vice chair of the North Korean Workers’ Party, Kim Yong-chol, being sent to a forced labor camp in “the latest example of how a senior North Korean official’s political fortune is made or broken at the whims of Kim Jong-un.”

The linked NYT article says this:

Now, he has suddenly become the latest example of how a senior North Korean official’s political fortune is made or broken at the whims of Kim Jong-un. This week, leading South Korean newspapers reported Kim Yong-chol’s fall from grace. One of them, the conservative daily Chosun Ilbo, went so far as to report that Mr. Kim had been banished to forced labor, with many of his negotiating team members either executed or sent to prison camps.

South Korean officials and analysts cautioned that it was too early to say with precision what was happening inside Kim Jong-un’s opaque regime. South Korean news media offered differing conjectures, including whether Kim Hyok-chol, the North’s special nuclear envoy to the United States, had been executed by firing squad in March, as the Chosun Ilbo reported, or was still under interrogation.

But they all agree on one thing: Kim Yong-chol and his negotiating team, which had driven Kim Jong-un’s diplomatic outreach toward Washington, have been sidelined, as the North Korean leader sought a scapegoat to blame for his disastrous second summit meeting with Mr. Trump, held in Hanoi, Vietnam, in February.

That seems pretty reasonable? It says that the official has found disfavor, says what one other paper reported with language of "went so far as to report", and also notes that it's hard to say for sure because North Korea is very opaque.

The FAIR article then says:

There was one problem: Kim Yong-chol appeared only a few days later at a high profile art performance alongside Kim Jong-un.

Yeah, that's hard evidence he wasn't executed, but that's about it. Situations like this can change on a whim in a dictatorship. Maybe Kim Jong-un had a good breakfast and decided that the official's forced labor could be done.

FAIR also says this in that article:

North Korea is also a favorite location for wacky and easily disprovable stories. The BBC (3/28/14) originally reported that all men were required to wear their hair like Kim Jong-un, with other haircuts banned.

The BBC article has a correction that it's university students and not all men (which is missing from the FAIR article), so is that true? And it's weird to say that stuff like that is wacky when stuff like this apparently happens:

A second, and unprecedented, TV series this winter showed hidden-camera style video of "long-haired" men in various locations throughout Pyongyang.

In a break with North Korean TV's usual approach, the programme gave their names and addresses, and challenged the fashion victims directly over their appearance.

That looks legit, with footage on youtube. Is there any reason to think that's fake? That certainly confirms my mental model of North Korea as a wacky dictatorship if it's true.

EDIT: FAIR's other statements in that article are dunking on the worst possible interpretations of what people say, which just makes FAIR seem like it has a chip on its shoulder about North Korea for some reason. I'd take what they say about North Korea with a grain of salt.