Looking at the trailer, seems this first raid will be.

First zone: Jeuno with Prishe as the boss
Second zone: Sanctuary of Zi'Tah or The Boyahda Tree, with the boss Fafnir or Nidhogg (So maybe The Dragon's Aery)
Third zone: Ru'Aun Gardens (Sky) with the Ark Angels as bosses.
Fourth zone: Castle Zvahl Keep with Shadow Lord as the boss (given he's voiced in the trailer, I assume he is the final boss.)

If this is the correct order of zones, seems a bit weird. Normally you would fight Shadow Lord way before you could get to the Ark Angels in the Zilart expansion.

It covers the base game and first expansion, there was a connection in the game for this. So we'll see if CoP and ToAU will be next raid, and then WoTG and last expansion, but they aren't as connected as base and Zilart.