Edit: For some reason, two of the images didn't end up here. You'll find them at the bottom of the dev diary.
Since China's capital moved a bit during the era, there's now a way for the Emperor of China to move it around (the AI can only go for de jure kingdom capitals in the China region (or the county of Luoyang, which isn't a kingdom capital but which historically was the capital) that are de jure part of China, while the player can go for any county that's part of the China region and that's a de jure part of China).
The AI will only rarely move the capital if it doesn't belong to a historical dynasty, and the historical dynasties (which currently are Li (Tang), Zhao (Song), Wanayan (Jurchen Jin; they never hold e_china in the history files), and Borjigin (Yuan)) will only rarely move it to a county that wasn't their historical capital (and those that had several capitals have preferences there; Li prefers Chang'an and Zhao/Wanayan prefer Kaifeng).
Also, in case you were wondering, the number of holdings in the provinces above will probably increase
significantly down the line; we just need to script baronies in the relevant area to be able to do so.