It is a good question. Indeed in cosmology almost all the information comes to us via light (even the microwave background is EM radiation, a kind of light)
I would like to hear what other people have to say especially as it applies to cosmology.
I would say that neutrinos are different from light. At some time in future people will almost surely be able to study the first second or so of big bang by the neutrino signature. there must be a neutrino background analogous to the microwave background.
Of course in neutrino detectors the neutrinos produce a flash of light when they interact with the detector material. So at the very last stage the information again becomes light. But let's not count that----lets say that the neutrinos are a distinct different information medium.
also there are cosmic rays, typically high energy protons accelerated from AGNs by some means not fully understood. That's yet again a different mode of information from light.