At thought at first that the title was clickbait.

" You mean to tell me that we can see light from the edge of the universe, but we can't tell if an object will be bright (or not) when it arrives at earth ? "

Reading the article, it seems that there's materiel that will react with the faint but steady hit of sunrays. Still , with our tech and advancement, you'd think we would be able to give a reasonably accurate prediction of whether a a very large stone will continue to shine bright when it passes by earth at supersonic speeds.