Well i doubt we will see it in 2.2 but there are a few more potential locations for dungeons such as:

Central Thanalan
Sil'dih Excavation Site

Eastern Thanalan
The sea of spires
The invisible city (might be related to Sil'dih)
High Bridge (The ruins on the cliff side might be part of the invisible city)

Northern Thanalan
Abandoned Amalj'aa mythril

Old Gridiana
Black Boar Gate (Could be a new area all together and open similar to white wolf but could be a dungeon in of itself)

Middle La Noscea
Woad Whisper Canyon/The Descend
Nym River Skylife

Outwe La Noscea
Floating city of nym

And there are many more landmarks that just don't have specific gates stopping us to getting to them like Iron Lake where its a mountain so they could open it up later. But the map was very well designed to allow expansion without needing to add significant chances to the normal travel routes to get there.

Also on the Castrums that were attacked were one adventurers couldn't directly visit Marinum we went there to

SPOILER

Assassinate Rhitahtyn sas Arvina, but the outpost is still here we just disable to bridge to it. If anything we trapped them there from land but they would still be able to airship and sail in and out. So it wouldn't be a stretch to say there are still troops inside so really any reason could get us to dive in a crash the gates.