I'm not sure there is a "go-home" factor with McDonald. He's said he doesn't care where he goes and that he aims to be a 1 club player.
That's been mentioned before but personally I wouldn't be reading to much into it.
At present he's just a teenager excited about the prospect of living out his dream but once the grind starts, the setbacks happen, other clubs come calling then his outlook will become more pragmatic than the romanticised view he currently has on what it means and takes to be an AFL footballer.