So here goes my rampant speculation and educated guesses:

1. Voidsent Looking Root Bird Thing taken over Bahamut's body. Looks like idk, Xande or whatever Allagans built Azys Lla gave over Bahamut's physical body to the void, maybe? It really looks like Pazuzu fused with Bahamut fused with one of those Bears that is taken over by plants.

2. Huge swathes of the Imperial Capitol reduced to rubble. Seems on point for the civil war activity that erupted there in 5.1.

3. Giant Porxie boss fight on the Source. Matoya dabbles in Porxies? Huh.

4. At 1:39 you can see Eden right behind our Ascian dude turning on his mask in The Empty.

5. Looks like we're going to battle an FF1 reference in the form of Lich in the new Bozja catacombs thing.

6. Instanced battle alongside Merlwyb in The Navel. Didn't notice the first few watches that the WoL is there tanking.

7. Some more cool bosses in Bozja catacombs thing. A prototype Phantom Ray maybe? Followed by some girl thing doing Ice/Fire move.

8. Time draws near, DRK LB3 place has the same background as the place Gaia is having her magical headache fits.

Misc observations: Since Zenos is in his Dissidia outfit, he uses two new katanas entirely in that I think? I remember seeing him use Shinryu, Susano, and I think his Lightning elemental Garlean make one still. My guess would be, Fandaniel brought him new ones or he's gone out and gotten better? /shrug. It's that or, in the way he manifested an aetherial katana over the broken deep gold one he used to kill Varis/fight Estinien and Gaius... maybe he's just into aether blades now.

Looks like the oldest of the Raen orphans is going to be Emerald's pilot, as Rex was seen pulling he girl away.