They aren't exactly the same, but the differences between areas in the artbook also shown in the gameplay demo suggest that these two could be within margin of error of each other. The right artwork is located on the Great Plateau, possibly overlooking the Shrine of Resurrection or might even be the Zonai/ancient Shrine of Resurrection itself. I went to that location in Breath of the Wild to check if the background lines up:
The left is the cliff overlooking the Shrine of Resurrection and the right is the famous intro cutscene overlook outside the Shrine of Resurrection. I think the latter lines up more with artwork on the right but it's hard to tell for sure. The southside of the colosseum matches the perspective in the artwork either way, so it seems pretty definitive that this is located at the Shrine of Resurrection, it's just a matter of the exact height. If the sky island ZeldaPY identified is this same ancient Shrine of Resurrection, then this seems to align with people's thoughts the sky islands are perhaps ancient features of Hyrule lifted into the sky. But the ancient shrine of resurrection also featured in the latest trailer (
source reddit):
Assuming this area is in the sky in present day Hyrule, it seems that rehydrated Ganondorf might not necessarily be a thing. These cutscenes of Ganondorf taking on his hydrated form seem to take place in the past, before these structures were lifted into the sky. We don't have to wonder if that is Demise, it's Ganondorf because that's Ganondorf in the ancient past when this Zonai structure was located in the Great Plateau and not in the sky. We also saw the ancient plateau featured in the blood moon cutscene in the February trailer (which also matches the artbook,
identified on reddit as well):
So what do we make of all this? It seems like Link starts Tears of the Kingdom quite literally in the Shrine of Resurrection again, except it's in the sky. Ganondorf has some powering up cutscene in the past on the plateau but this seems like an entirely separate event from his reawakening in the present. Ganondorf might just be mummydorf in the present. The recent trailer involves a clever cut showing the malice shooting up to the sky, perhaps these cutscenes are thousands of years apart from each other.
It's possible Link and Zelda explore tunnels underneath the Shrine of Resurrection and that area gets lifted to the sky in order to save Link, but I'm somehow doubtful. I think mummydorf is found somewhere else, perhaps beneath Hyrule Castle or somewhere in the Gerudo desert. Whatever the case may be, Link ends up in the ancient Shrine of Resurrection in the sky, a location that seemingly has some importance for Ganondorf and perhaps served as a site of resurrection for himself in the ancient past.