Not really feeling that but it is indeed mostly a heavy-ish somber trailer except toward the end of it. Maybe some of the lack of "fullness" to the sound could also be since it was taken from witter, which is usually pretty crappy in quality with video clips. They haven't uploaded a real high quality copy of the dubbed trailer.
Anyway though, I thought the dub for the first season was generally very good so I expect the dub for the movie to be very good too.