This is an interesting find, and a great example of evolution. If you take a look at the picture-
-the feathers look almost hairy. Even though they're longer feathers, they don't have the same structure that long bird feathers do. You know how if you get a turkey feather all the barbs stick together and you can run your finger down the side, making a slot? These dino feathers don't have that particular feature- they're more like the down you'd find on a bird today. Reason being, having those barbs stick together (a la turkey feather) was a flight adaptation to make the feathers into lifting surfaces. Instead of going that route, dinos used feathers for body temperature regulation, which was their original purpose. Flight evolved separately, as the ancestors to today's birds flapped their limbs to propel them up steep inclines. Eventually, the feathers and body structures of those creatures were selected for enough to allow for actual flight.