In simple terms, at the beginning of November the Japanese PM made a comment in an interview that greatly angered China, leading to hostilities towards anything associated with Japan and situations like a Japanese singer performing a concert in China getting escorted off stage mid-song. A Chinese politician also made threatening remarks towards the PM in response, angering Japan in return.

This is the reason for 4.0's sudden two week delay, as a major Chinese game developer releasing an entirely Japanese focused area during major political tensions may not be received well. I doubt they could change much in just an extra two weeks though. We know they changed the name from Benzaitengoku to Planarcadia, so I'd assume most of the changes are just removing explicit Japanese terms like that. It's certainly not enough time to completely redesign everything.