tbh I don't like the idea of doing 5 zones based exclusively on different dragonflights because imo it would be too generic and unconnected with the rest of Azeroth. shadowlands, but with dragons instead of reincarnated dead.
besides, we've seen the map and the globe of the world many times. where could you hide an entire archipelago? in classic alpha they were right above Lordaeron.
what if they were floating and hidden in the clouds, like Dalaran, but also giant? they could even stay in the same place, next to Quel'thalas. and that would be the reason to revamp northern EK - it would be part of the expansion launch progression campaign, leveling (if they don't cut it).
Eversong, extended Ghostlands (with that small zone with a tower north to the Eastern Plaguelands), Amani mountains and the Dragon isles (2-3 locations floating to the west of the known area) could be the next continent. renewed Silvermoon as the new, neutral capital - and that would fit with the cross-faction PvE (which is already discussed, and i think even teased in one of their twitter posts).
we still don't know where does the path of titans end. it goes into the sea south of Dragonblight, passes by the Strand of Ancients and then nothing. what if it led to an uld-something, another bullshit power storage which was ripped out of the earth and made to fly to protect it from the rising kaldorei empire way before the Sundering? Galakrond might ally the twilights and try to seize it for the usual villain goal.
- if the DI are next to Quel'thalas, that could explain why most of them choose a highborne humanoid form, making it just a convenient way to blend in with the locals if they frequently visited Silvermoon due to proximity.
- if the expansion revamps Quel'thalas, we might get an amani (and maybe even drakkari as they share body shapes) allied race or extension to the base troll race. something something, dumping old hatreds, peace, reconciliation - to be expected from the current lore team.
- I'm still not sure what was Deathwing's goal in the Dragon Soul raid. is the Wyrmrest temple a power source by itself, or is it a mechanism of hiding/shielding the DI? I'm unaware if it's the former.
- getting a new, flyable Quel'thalas without costing us a raid tier would be nice.