There seem to be a few major retcons in Nazjatar, or at least it is quite confusing how they are handled.
1. First and foremost, Zin-Azshari's pristine state right before the Sundering.
Apart from changing Azshara's location from her palace to a random market in the city, the metropolis is in a perfect shape. At least that is what we can see in the Warbringers video. Also, the ghostly Ara-Hinam refugees mention that after the demons destroyed their town, they went to Zin-Azshari where the people doesn't even believe them. This might be funny considering the capital was utterly destroyed by the demons pouring from the Well standing right to their side.
https://gamepedia.cursecdn.com/wowpe...599fd1aaf39390
https://cdn.discordapp.com/attachmen...8/Untitled.png
2. Second, Nazjatar and & N'Zoth's location.
Lorewise Nazjatar was supposed to be in the Maelstrom or at least very close to it. But instead there's no mention of it nor visual effect on the horizon of the zone or anything. And N'Zoth's prison was more or less supposed to be between Kul Tiras and Zandalar. This last one could be explained if what we have in the Eternity Palace is not the Old God prison but something else or just a far corner of the prison maybe.
There might be some more but these are the most important ones.