I've started to read the article in which CA explain when they were working on 3Khttps://www.totalwar.com/blog/update-on-historical-releases/
Meaning there's a huge chance of the game receiving an add on like Fall of the Samurai as in Shogun 2 if you read the article.
While periods like the Warring States, Seven Kingdoms, Mongols Invasion etc would be nice. In a marketing view, people in the west have literally no clue about the history of China other than 3K, with only a minority knowing Chinese history beyond Three Kingdoms. If you look at games such as Oriental Empires, it didn't receive many sales due to the fact that not many ppl in the first place is interested in Chinese history/ not interested in the setting. You guys made the right call for Three Kingdoms, as it is well known throughout China, Japan, Korea and most of Asia
If CA is really aiming for money, think about the possibility of doing Cathay for Warhammer 3
What is Cathay? Ancient China
Marketing wise, its good since it will draw people who are interested in Warhammer onto 3K and people who are only interested in historic games/3K onto Warhammer, and fantasy has been proven to be effective with the sales of Warhammer, even on the reddit it's full of Warhammer fans
This will also draw in the "Chinese market" in buying both 3K and Warhammer, since the visit from the Chinese community last time for 3K CA should have a grasp on whats going on.
Before the announcement of 3K, the chance of Cathay being on Warhammer 3 is close to 0. Now after 3K has been announced the possibility isn't 0 anymore, especially after what CA did on Vampire Coast and custom lord. Assets from 3K can be modified/reused. The map can be cut like on Mortal Empire, Cathay can also act as an expedition force without including the whole map. It would make sense since they are one of the very few good "Order" factions fighting off against Chaos. And on the Darklands, we are lacking good factions, if the game only has 4 Chaos faction the game won't sell well. Kislev will be a good addition as a pre-order bonus.
Obviously, all of this will heavily depend on the sales of 3K
Unique units like the Terracotta soldiers, stone dogs, celestial dragons and such would really fit Warhammer 3. As for the map
Dave Taylor did a conversation on Cathay army on the White Dwarf for Games workshophttps://imgur.com/a/BKy1UOK#7BPQviv
also please check out a reddit user by the name of lnsan1ty https://www.reddit.com/user/lnsan1ty
who have made concept arts for Cathay and they are great, and he's still doing more as we speak in the time to come. the Community also likes it
If CA really wanted money, no way you guys will miss this!
Again all of this depends on if 3K was a success