This is how the trailer originally sounded. At the 5:34 mark it starts playing "Fight Song," which is really catchy.
But if you go to the official CBS page, and play the video, the music has been replaced by some weird, janky tune which doesn't fit the mood at all:
It's not like CBS uploaded a new video. It's the same video, with the same URL, which they uploaded on May 13. The upload date still says May 13. In fact, if you check any entertainment websites which embedded the video back in May, you'll hear the same cruddy tune at the 5:34 mark.
So how do you change the content of a video once it's already been uploaded? A bunch of other bloggers noted the trailer used "Fight Song." For example:
There's even one blogger who specifically tracks what music is used in trailers, and he/she noted the change as well! Thanks, nameofthesong, for reassuring me that I'm not imagining things: