You mean this EE2? http://forums.civfanatics.com/showthread.php?t=344739
Babylon is moved to allow room to play with sumeria.
China depends on what you are thinking of - if you are looking for modern day Beijing or the core of the old kingdom.
But yes they are mainly done for balance and the ability to have any civs on the game together. I actually don't know where celtica spawns thinking about it...
But the actual map is far better than the earth 18 map. Mali are viable. There is a lot more useful land all over the place which makes for a more interesting game. Besides we can move a few civs if you are desperately keen or use the ones that are more historical [emoji6]