Isn't there great chance that a nation would be made unplayable with this state based war goal system? What if Austria is fighting Prussia, Italy, Russia and Ottoman Empire and all of them are asking one state each? At least in multiplayer games you always want small reward for fighting a costly war. Now you cant ask a province or two but are forced to take whole state or nothing. Well in Victoria 1 it was land and pops you wanted, that might be changed now.
dont think this was addressed earlier. there are a lot of war goals that are not related to taking states too, and gaining prestige is very important (as is hurting others prestige) because of how good having a larger high prestige sphere is, so waging wars just for prestige is not too uncommon.