Those comments really mean jack....they still don't know what it is and what's to say something else couldn't mimic those results. They're putting all their eggs in one theoretical basket and that's dangerous, theoretically
.
Here's the clanger....if dark matter interacts with both itself and normal matter via gravitational influences, then eventually both the dark matter and the normal matter will fall to the centre of the cluster...whether they pass through one another like "ghosts" or not. Since the dark matter is the most massive, because there's supposedly more of it, it will be right at the center, with the ordinary matter on the
outside, for the most part.