So, something interesting about this leak is that it mentions zones being merged together. As people have said this leak is very possibly just built around the datamined stuff from yesterday pointing to Lordaeron... but what I haven't seen talked about much is the fact that the skybox in parts of Lordaeron around Arathi got changed. On both Live and PTR, there is a HD skybox that appears in most of Wetlands, Arathi, most of Hillsbrad and Hinterlands. In Hinterlands its bugged and the clouds appear above a vanilla-style neon red sky, but its the same clouds as the other three zones. You can go check it yourself... this may have been in the game since BFA (if Arathi revamp had a new skybox but it's interesting that the skybox "bleeds over" into three other zones but disappears when you go to other zones like Tirisfal.
This leak mentions that Hinterlands and Arathi are combined, which would explain the skybox persisting, but Hillsbrad is part of another zone (Gilneas) and Wetlands aren't mentioned at all. Even if this leak is fake I think there is going to be some kind of zone merge based on that persisting skybox unifying four old world zones.
And even if we get Dragon Isles, Lordaeron can still be involved as they were right next to each other in the old draft: they were smack in the middle between the Plaguelands and Northrend.