I finally got around to giving this a few listens. I enjoyed the Killer Cuts remix CD of the original Killer Instinct back in the day and was curious to hear what this sequel might sound like.
There's far less of an emphasis on energetic dance tracks this time around, largely substituted with a more modern-rock approach, and in general a stronger focus on the respective character/stage moods than outright energy. It's interesting how the composer has implemented several sound effects, instruments, and brief motifs from the original in these otherwise new pieces.
That said, I have to say I enjoy the "Original Arcade" tracks (which are actually straight from Killer Cuts) far more, even with occasionally hokey '90s dance throwbacks. Aside from "Warlord", there aren't any tracks from the Season One soundtrack that I'd particularly want to listen to again, though I imagine they serve just fine as BGM in the game.