@augustus Never. We may someday be able to accurately reproduce his style in new pieces, (as a well trained and talented composer probably could now), but Chopin was an artist that continually evolved throughout his lifetime. True new Chopin would be a continuation of that evolution. However, without the pressures of the human experiences that made him evolve the way he did as an artist, I can't see how that evolution could be continued. Why would an AI trained on earlier Chopin write something as shocking as the scherzo at the end of the b flat sonata? It would have no reason for that statement, while Chopin did because of what he was going through in his life.
@augustus I just re-listened to it and to me, it does not feel like it works as a three movement piece for a similar reason. Ending on a slow emotive movement like that leaves a sense of qn unresolved emotional state that asks for a conclusion, but the conclusion he chose colors the whole sonata. If you interpret it as a peice about death, than the the third movement has a sense of melancholy acceptance to it. The last movement undos this and leaves you with a sense of anxiety and dread. It feels like a death rattle to me. Like you know what's coming and you can't do anything about it and can't quite come to terms with it even though your trying. Really unusual and specific emotional color thats definitely not an obligatory bookend the way some of Beethovens early last movement feel.