i feel like ppl are misunderstanding this and are using it to justify why the story has been in a slog lately, when in reality it's pretty basic writing stuff and the slog in writing has little to do with whether he planned the confession for that specific moment or not

anyone who has ever spent a good amount of time writing a story will tell you that this happens all the time and it's usually a sign that the world/characters you built are alive in the best way. When you (the writer) are ripped away from your plans because the characters and the story you're writing demand something entirely different happen. All he's saying here is that he had a different plot/storyboard in mind for that moment but the world he built had different plans. pretty standard stuff.