Do they have an entirely different group of people that compose the music for the trailers? And if so, is it intentional that the teaser music is so foreign to the rest of the game and the elder scrolls franchise?

I personally loved the music that plays in the gates of oblivion teaser when we see dagon rising above the stairs. And in necroms when the arcanist was exploring apocrypha. They have weight, are intense yet melodic. But I never recall hearing anything like that during combat or story. Instead it's all what I would describe as "generic" overland music. What're y'all's thoughts on the situation?