I like this subtle hint. Leaving the rest of the score intact is good; having new music for a new movie keeps things fresh. The callback themes keep star wars connected.
If possible, I would like to hear Vader’s subtle theme as he exits the ship. Musically, they hinted at it (by using the loud horns) but they didn’t finish the theme. It was a tease that made you finish the notes in your head, but it felt off.
I agree that they hint at it, but I think I’m going to leave that one only because there’s already 3 instances of the imperial march throughout the movie, and I don’t want to overdo it. It also let’s the focus be on the battle of the heroes theme being added.