GAC, your logic would almost dictate he never get called up because he MIGHT struggle. I'm not sure making decisions based on what if scenarios is a good philosophy. We know the guy is good enough to hit ML pitching. This whole "build confidence" scenario is shaky, IMO. I don't think he's that weak-minded. The guy just needs ABs at the major league level.
Here's a what-if scenario for you. What if they keep him down there and he continues to light it up for an extened period of time, then they call him up and he struggles. Maybe then Austin begins to wonder if he can really hit major league caliber pitching. I don't believe any of that, but if you want to play what if, we can play what if all day long.