There's another inscrutable mystery in physics, the nature of consciousness. Time might as well be an artifact of that. I'm surprised this article doesn't mention this possibility.
The first problem with the nature of consciousness is describing what you mean by it. Try, and I guarantee you that someone will find a sponge, Apple product, or bathroom slipper that meets that definition.
Electro-magnetic radiation, on the other hands, is highly describable in precise, testable, repeatable terms.
When you can state Maxwell's Laws of Consciousness, we'll talk. And rename them "Grishka's".
It's "dark" in the sense that the (fabled) Dark Ages were dark. They didn't have more cloud cover then. And dark matter is 'dark' as in 'inobservable, except by gravitational attraction'. So we admit it might not even be "matter" by any definition we have; it's just what we're calling this invisible, untouchable, silent elephant in the room. That is very heavy. And might not be an elephant.
Honestly, "invisible matter" might have been a better term, but that too would have been misinterpreted.
Here's an interesting lecture about it: https://www.youtube.com/watch?v=YusrOYGAhqM