What else could be hidden in the Sea of Clouds

[Enkidoh]

We already know that Stormblood is taking us back to Ivalice. We have sky pirates just like XII. Now...I want them them to find Lemurés...I need this to happen.

Considering that the development team already stated outright that Ivalice and Hydaelyn are separate worlds with no connection to each other, I'm taking that 'Return to Ivalice' thing as a metaphorical reference in name only and not physically going to FFXII's world:

Q55: There are a lot of names from Ivalice such as Dalmasca, Belias, and Zodiak that have been mentioned, is there some connection between Hydaelyn and Ivalice?

A55: To be absolutely clear, there is no connection between FFXIV’s Hydaelyn and FFXII’s Ivalice. Likewise there is no connection with FFXI’s Vana’diel. Each are their own individual world. Based on this, there are connections between the things that appear in the world, and we’ll be revealing more in the future.

1:57:29
Q: A lot of names from Ivalice have been mentioned such as Dalmasca, Belias, and Zodiak. Is there some kind of connection between Hydaelyn and Ivalice?
A: Maehiro: To be absolutely clear, there is no direct connection between FFXIV’s Hydaelyn and FFXII’s Ivalice or even FFXI’s Vana’diel. They are not the same world in different dimensions or time—they are their own separate worlds. However, there are certain connections to people or objects that appear in these other worlds that figure into the story of FFXIV as it has been conceived and is being told.

Yoshida: We’ll be revealing more as we move forward.

So basically, I'm only expecting a fanservice reference dungeon from FFT or FFXII that is in name only and is not the FFXII/FFT version, but a lore specific place for FFXIV that just happens to have a name from FFXII or FFT with certain enemies from those games in it, like the Crystal Tower being an Allagan ruin and not the actual FFIII version. But I guess we'll find out.