A picture I found at LetsGoKings.com shows an outline has been added to the numbers stitched onto the back and sleeves of the black sweaters.
credit: Wile E. @ LetsGoKings.com
It's small but I guess it adds a little something to the jerseys. And it's different so I suppose that makes it news.
By the way, it's worth noting that teams tend to do all sorts of weird stuff for those rookie jerseys this time of year so it's hard to say for sure if this is a permanent change or just something that made it easier to throw together a bunch of sweaters for guys who won't see real NHL ice for a few more years.
That being said, this particular change seems like it'll stick. We'll know for sure soon. The season's right around the corner.
Thanks to Steven for the tip on this change.