They know it but they seem to be forgetting that they know it. I think that they are waaaay out on a limb claiming to know the shape of what they cannot see. They know what is happening around it to a degree but they are assuming that what they "See" is an accurate representation of what "Is". My opinion is that their extrapolations that some black holes are in the shape of a birthday hat are likely a bridge too far. I may not be an "expert" but I call Shenanigans.