Gabriel, King Edward, and the rest are on Harmonia. You can access Harmonia by going to the ship's bridge > travel > open the galaxy map , then click the button 'Explore' until you discover it. A good chunk of new content is on there.
There's also more content after you killed the Warlord and it's about finding the next Praharma. Go to Akra, get access to the second floor, explore it a bit, find the Pulse, you then should be well on your way to find access into the VIP area. More content follows.