These findings do indicate that the Dark Matter theory is increasingly reliable, in that some galaxies are shown to have different densities (& thereby there's nothing wrong with Kepler's Law, and further proof that my "going with the gut" when compared with empirical science is just silly!)
These findings help reinforce that Kepler's Law are working well and seem to indicate that that dark matter is not necessarily tied with matter, but is hanging around in different densities in different galaxies.
> Ironically, the lack of dark matter in these UDGs strengthens the case for dark matter, the researchers say. It proves that dark matter is a substance that is not coupled with normal matter, since they can be found separately.
To me, it's a bit like how our planet is not uniformly the "same stuff", but we have deposits of Gold and Coal and Granite spread around the place in an uneven manner.