Disclaimer: Bandai Namco recently revealed that we will be able to trigger classic scenes in the game by performing certain actions during a fight.
For example, if #16 is defeated by Cell and Gohan is on #16's team, we'll see the scene where Gohan went SSJ2 for the first time.
What we see in this trailer are likely scenes from this mechanic, and not from Story Mode.
I love that they use 'We Were Angels' as the song for this trailer. This game really is a loveletter to Dragonball fans.