NRS music style for fighting games is effectively best described as "movie battle scene"
Here's the main MK11 theme
And here's the theme for the Helm's deep battle in LotR
And here's the battle theme from Edge of Tomorrow
For comparison to the previous three, here's KI's (fucking amazing) theme
Compare that to Mick Gordon's works and it kinda makes sense why they think he doesn't fit even if he is indisputably one of the best things to happen to video game audio. They're going less for a "this fight is a music video" and more for a "this fight is a movie scene" vibe. And I respect that approach even though I like the former approach better.
I think NRS botched the "movie music" approach though. I remember the LotR battle themes, the Rogue One battle themes, all these "grand battle movie" styles, but I can't even hum the MK9-11 themes from memory. They need to amp up the volume and make it dynamic like KI.
EDIT
I'm actually not sure if MG was involved with the KI3 menu theme. I'm pretty sure he was and the point stands regardless due to style