Time is very much a dimension: spacetime is well described as a 3+1 dimensional manifold.
Reading your link, I have no idea what those researchers are talking about (nor did it inspire me to look at their actual article). The "1 time + 3 space dimensions" structure of the universe is exceedingly well established experimentally by the essentially perfect verifications of the predictions of relativity that we use every day (in GPS, for instance). It's possible (though unlikely, from what I've seen here) that they have some deep new insight into the nature of time, sure. But any successful theory of time will have to be almost indistinguishable from standard 3+1 dimensional spacetime under "ordinary" conditions, or else it will contradict a huge body of experimental evidence. So even if what these folks are saying somehow makes sense, saying "time is not a dimension" would still be wrong in many important ways.
Reading your link, I have no idea what those researchers are talking about (nor did it inspire me to look at their actual article). The "1 time + 3 space dimensions" structure of the universe is exceedingly well established experimentally by the essentially perfect verifications of the predictions of relativity that we use every day (in GPS, for instance). It's possible (though unlikely, from what I've seen here) that they have some deep new insight into the nature of time, sure. But any successful theory of time will have to be almost indistinguishable from standard 3+1 dimensional spacetime under "ordinary" conditions, or else it will contradict a huge body of experimental evidence. So even if what these folks are saying somehow makes sense, saying "time is not a dimension" would still be wrong in many important ways.