Yeah, that is a bizarre conclusion. I also think it's weird of them to assume Lucas Giolito will be a #2 starter, full-time, after just two years of playing in our system (after losing 2013 to TJ). That's a Strasburg-esque rate of development.
One thing that BA does when they project your 2016 lineup is that they assume that you resign/keep your own players and they don't give you any free agents. Also, they love pitching prospects.