Square Enix released a new trailer for Episode Gladiolus.The trailer gives you an idea of how the DLCs story will be. The DLC is apparently 2-3 hours long and will likely include a teaser for the next DLC.
Episode: Gladiolus is set to release on March 28th. The game has an updated UI as well as different mechanics for how Gladio acts in gameplay.
The Games Trailer
Some Gameplay