I quite like your ideas
Here is how I would see the zones :
First of all, zones in the Dragon Isles would be a reminder of what had been done previously in WoW, but done to a greater extent. So, we would have a fully underground zone, a zone floating in the air, a zone located in the Emerald Dream, and a mix of nature and titan landscapes. In the end, each zone would have as theme one of the Dragonflights.
In this exp, you find out the Twilight Hammer, the Nightmare and the Infinite Dragonflight have been working together for years in order to take control of Azeroth.
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Uldaz City (neutral capital city) : a beautiful Titan city built upon the location where Azeroth is expected to emerge upon her birth. This is why it is targeted so much.
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Uldaz (zone) : think of heaven on earth, a magnificent paradise where life and magic coexist with no trace of hatred or war. The zone is located in the center of the Dragon Isles. It is a sanctuary to all Dragonflights and all Titan-forged. You can find Earthens, Tol'virs and Mogus that never left the Isles since the world collapsed after the War of the Ancients.
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Everblossom Forest : a beautiful red-colored forest home to the Red Dragonflight. You can find here a long-secret community of former High Elves that fled Quel'Thalas after the Third War, now called Dawn Elves. They have embraced the ways of the Red Dragons and have vowed to defend their new home from external threats. They are fighting the Twilight Hammer invaders.
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Eye of Ysera : a lush dreamy forest located inside the Emerald Dream, original home to Ysera. It is a high-guarded place within the Dream that's being assaulted by the Nightmare. To help defend the zone, Wild Gods are being called back into the Dream - including the August Celestials (making it possible for Pandarens to (finally) become Druid).
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Mount Norgar : a mountain range stuck in an ever winter where mana and telluric lines are dangerously unstable. The area, inhabited by Blue Dragons, is being attacked by the Void. Mages will have a key role to play in the quest lines.
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Black Earth Caverns (bellow Mount Norgar) : sanctuary of the last Black Dragons. The area is being harassed by the Twilight Hammer that wants to corrupt the Dragonflight and enslave it once and for all. You find in this zone the very first tribe of Taurens/Yaungols and learn more about their pre-Titan origins. Shamans will be important in this zone.
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Time's Rest Island : a floating desert high above the Dragon Isles where you can find Bronze Dragons fighting Infinite Dragons. Expect Chromie in full action as you've never seen her before.