Dark matter is always under reconsideration, but so is the other kinds ~ here's a thought for you ~ what we are seeing here are actually OTHER UNIVERSES.
They are adjacent to our own. However, some of them broadcast in frequencies, and according to natural laws, so similar to those that prevail in our own universe, that we can see them. Others are different enough that we simply cannot detect their local equivalent of "dark matter" or "ordinary matter".
I've wondered that myself....only not that the matter was of "other universes" but rather, matter from our universe that was knocked slightly out of our reality by something like the Big Bang.....perhaps the first quarter of the matter of our universe was on the outer shell/fastest part of the explosion - moving so fast and under so much pressure that it moved slightly out of phase with the rest of the matter.I've wondered too if dark matter could be the ejecta of black holes, similarly knocked our of phase by gravity.
I'd like to see the question of dark matter figured out before I die.