"The upper city was just the parts of the upper city found in the final battle" is much simpler than "Larian lied several times about a secret scrapped section of the game that would explain away the incompleteness and also held the key to fixing Karlach, despite the lack of datamines pointing to any of these plot points or locations, and it was all deleted within the span of a month after its apparent development was highlighted".
Unless I'm missing info, the Emperor wasn't a change made within a month. It was obviously after EA, but, for reference, IIRC Theo Solomon (Wyll's new VA) started working on his character in 2022, so did Karlach's, IIRC. Both of these characters feel very rushed and they're still the work of almost 2 years, and they're not necessary to the main plot, unlike a new section of the game. Next to that, a month to delete all traces and ramifications of an entire new location is insane, especially after having apparently tried to showcase it's appearance in the game.
Briefly entering the Upper City for a battle is not the same as having it open as an area to explore. We can't explore the opulent buildings as it was said we would be able to in July. They also, to my knowledge, never said they were only referring to the final battle. So this not being the case would not be a lie on their part. As I said they've mostly just avoided giving a clear answer on anything but Karlach's alleged cut content. They said that was untrue and I believe it.
As for there not being anything indicating cut content in datamined files, there wouldn't be much evidence, if any at all, of anything significant that they cut. I always explore datamined files and there's almost never evidence of anything they cut between patches and hotfixes. If I do find something it's pretty insignificant, like a line of dialogue flagged "impossible." They are thorough in removing everything and making the correct edits to files because not doing so affects the game. The smallest change or inclusion/exclusion of a single file can change an entire scene. I've added content that has been removed or edited back into the game myself by using files from old patches.
