There are BILLIONS of reasons to to do this, Xi is currently in the process of doing a Mao style crackdown where the power of the STATE is emphasized, China is spending it's foreign exchange on weapons not expanding their middle class.What protects Disney is China's goal of being the framer of global structures and stability. That is why there has been a crackdown on graft and displays of extravagance. Disney planned a huge display of extravagance when the political climate is against such displays. There is NOTHING gained by taking the park and kicking Disney out.
By making an example out of Disney, China is telling the rest of the western businesses to 'Get with the program'.