Did you read the rest of the article Simon? I think it explains why 600 at bats are not likely to occur for Schwarber. It was chosen as a round number, to show quantitatively how great of a stretch he had in only his rookie year.
Realistically, Schwarber could get around 500 at bats, hit 30 or so bombs, but still strike out way too much.
Which happens to be what I wrote.
If you had any other questions, would be glad to answer them!