(I was a grad student of John Ostrom's once upon a time.)
This may be "the first evidence of feather morphologies and distribution in a short-armed (and probably non-volant) dromaeosaurid" but this dinosaur says nothing about the origins of flight feathers. It lived 25 million years AFTER Archaeopteryx, so there were certainly flight feathers around for a very long time before it. This is really no more surprising than the fact that ostriches and emus still have feathers.
The real question, which remains unanswered, is the exact relationship between dromaeosurids and birds and whether flight originated from the ground up (use of drag to control running) or the top down (use of drag to create lift).