Or well, we _just_ discovered it.
But I guess it would make the title less appealing. Who would read "black hole flared 25000 years ago for 1 hour"? :P
"We Looked Back In Time 25,000 Years and You Won't Believe What We Saw"
"We Just Learned One Of The Last Things That Happened Before The Neanderthals Died Out and It Was Amazing"
Fortunately science is slightly more immune to clickbait titles than other topics. Though only slightly.