I wonder if Avaloren is a setting for 13.0, The Last Titan?
It would make sense if Odyn's expeditions sailed north, since he was based in Ulduar and Ulduar was in the northern part of Ancient Kalimdor (before it turned into Northrend). So there should be some proximity between Northrend and Avaloren.
On top of that, I fail to see how Northrend alone could work for an entire expansion. Since they're not revamping EK and KA, I doubt they'll revamp Northrend. They could give it a new paint job, but if that type of lightweight revamp wasn't enough for Battle for Azeroth I don't see why it would be for The Last Titan. So new zones are probably needed.
Then again, would it make sense to introduce an entire side of the planet for just a single expansion pack?
Avaloren could be something for 14.0 and onward, but that also feels strange. Odyn's report on Avaloren suggests it has titanforged on it, and perhaps even Keepers. If we're sort of settling our affairs with the Titans and their story in The Last Titans, wouldn't it be weird to start over and turn a page by... giving us even more Titan lore on the other side of Azeroth?