The one hint I saw in 5.4 points to Werlyt and Bozja, as the Imperial capital is "half reduced to rubble" and we're unlikely to fully explore either region before the ending of Shadowbringers (or rather 5.X; Shadowbringers' story arc was 4.4 - 5.3).

Yes, we've gotten a lot of information on the Garlean Empire, and there are ready-made parts of it used in cutscenes... but we know much more about it than the rest of Ilsabard, and with the Empire seemingly collapsing I don't really see the need to go there at the moment, especially given both Zenos and Danny Boy are not resting on their laurels at the capital.

Now, I could be wrong, probably am wrong, and don't know how to make heads or tails of the New Years' hint... but...

(Gotta beat Emerald Weapon EX for the gunblade on my alt 'fore 6.0, cool gunblades are hard to come by and I really don't feel like FATE / Bozja grinding on two characters...)