I highly doubt they'd reveal music from the new album this way. They recently released an LPTV teaser that had no new music in it, obviously not revealing anything and just a few days later Mike releases 2 clips online. That doesn't make any sense to me since they are always very careful about these things. They don't want the fans to make up their minds about an album this way, we speculate enough what they say in interviews what it is going to sound like.
I think it's the Lonely Island song, if they teased that they have nothing to lose.
For a movie like that I don't think we are getting a traditional LP song, it's a movie that mocks the pop music industry so I don't expect the song to be 100% serious either.