It's actually mentioned in the post, but I'll reiterate here:
There was a lot of resistance to how Kouya was designed for Homecoming. Dzahn had mentioned that he something in mind about what was attractive to him, but he admitted he lost sight of what made Kouya attractive to others. As Devilizer and Nova have been getting much better with their art, it had been decided that we would be redesigning all sprites so that it was similar to the original, but with our own flair.
So, as you can see, Kouya and Kounosuke do look similar to the original game, but they do have differences as well that are unique to Homecoming.