Yeah, that sentence where he says that the story is already written sounds strange. It looks pretty obvious that he has been adding content in the way. For example, I think he is rushing a lot the lewd scenes because of the pressure to deliver something hot in every update, due to the slow process, and the realism has deteriorated in consequence.
Maybe he wrote some kind of draft version with no much details, he has mentioned that he would like to have another storywriter to help him.
Maybe some patron could ask him if he truly has all the story written or if he has been adding and modifying a lot of stuff in the way. And also ask him why not postponing all the side stories, like second jobs and others, for an expansion version when the main story is finished. He could make a poll for that too, if he has doubts.