Note that in Palutena's trailer, Dark Pit was shown to be able to use Pandora's power to fly as evident by the purple glow in his wings as opposed to blue (Palutena using Power of Flight on him) or green (Viridi using Power of Flight on him).
This is despite being unable to do so by the end of Uprising. Another case of canon being ignored, just like Pit even having the Three Sacred Treasures as a Final Smash after Hades destroyed them.
So being a more aerial centered character than regular Pit isn't too farfetched.
I also accidentally found out a few details about Pit and Dark Pit that differentiates the two in design outside of just palette.
Look at their scarves.
Pit has a solid white scarf.
Dark Pit's scarf is solid gray except for the right side being black like his tunic with a gold end.
Same gold end is present on his sleeves and his tights, which Pit does not have.
There is also a gold line-like pattern on the legs of his tights which Pit does not have either.
And, a detail that most people probably already know, the design on the hems of their tunics are different.
All of these are minor touches of differentiation, but at least show that Dark Pit isn't literally just a palette swap. Kind of like Blood Falcon.