Pure AI isn't enough, you need all the quirks of human nature and physiology, and human experience. There isn't enough data in poetry corpuses to infer what this is - and new aspects are revealed by new circumstances.

If we ever have strong AI, reverse emgineering human nature and an AI having the human experiences of a human lifetime seems in the same ballpark of difficulty.

Of coirse, human nature may be passé at that point, especially for AI readers, and ersatz poetry more popular (just as electronic instruments have displaced "real" physical instruments in popular music).