They have well demonstrated that they affect the brain on some level, but I think making the jump to call it a sense requires some actual effect on our physiology or behavior that the body takes advantage of as a means to DO something.
I'm inserting my own definition and understanding of what a sense is here, but I'd wager there there aren't too many ways of defining a sense without somehow including perception as a critical aspect. At least not any that people would buy wholesale or would be easily demonstrated scientifically.
A counterexample to this would be ionizing radiation. Radiation is present in our environment, we generally do not perceive it (at least not on any conscious level, and excluding the sense of heat and visible light, both frequencies along the electromagnetic spectrum), and it certainly has effects on the body that are easily perceivable (tanning/sunburn, cancer, etc). Can we sense it? I don't think many folks would argue that we can.
I also notice that the article uses quite a few weasel words, throwing "suggests" and "hints" in to justify the title. Not fantastic journalism IMO.
Bald claims with insufficient evidence would be bad journalism.
It seems like an obvious course of investigation. One wonders whether there was any attempt to recruit such individuals. Not all of them live in inaccessible places -- just most.
Can it affect people? Evidently so. That is what you just read about.
