It isn’t very interesting to speculate about a trillion-human future when we’re so close to a post-human future. Plus, Mozart was the product of his genes and his environment; both can be manipulated to create some process with a higher yield of Mozarts than ordinary human reproduction provides.
I’m preeetty sure that’s not how that works but then again Elmo does not behave like someone I would consider being knowledgeable in anything, so no surprise there.