[Voltaire]

"Typical matter emits radiation as it is going into a black hole and we understand and are accounting for this. Therefore, the radiation we receive includes all information about the amount of normal matter in a region whether or not it is in a black hole."

What you are saying is that we are reading the radiation that is going into a black hole along with the radiation that is not going into any black holes. But what about the matter that is already in the black hole? We are not reading any radiation from that matter. We can only be aware of that matter through its gravitational effects.

The problem, as I understand it is, that there seems to be more matter as measured by its gravitational effects than is accounted for by radiation. Since a black hole is exactly the sort of phenomenon that affects its surroundings through gravity but not through radiation, why is it not possible that black holes account for the missing matter?