Interesting that he's the one of the OFs that they are talking about moving to first. I guess that, because he was projected as the corner OF, his D is probably not at the level of Wood / Green, but was his D a liability?
I think a combination of a lot of factors. Its always been mentioned as a possibility. I think in large part to him having a bulkier frame and being young for his class. He's probably going to end up being 6'2 230 as he matures, while not being a freak athlete. That says more 1b than OF. Then of course OF happens to be the strength of the system, so you might as well start the transition.
I hope it's only part time though. I think there's value in him still running around the outfield and chasing balls down. Try to maintain as much of that athleticism for as long as you can. There's no guarantee the other guys pan out, and OF could still be an outcome, so I don't think they should shut it down completely.