Actually, that would be the best explanation. Although I can't guarantee that there weren't container loads of steel in this area. Like I said, I got the tiniest glimpse of a tiny segment of this area, which I would imagine isn't exactly tiny.
But you're right, it did come to mind that if they had the parts in storage, surely Movie World would have announced something, at least started a rumour.
A little off-topic as well, but following this I got a little bit of a fascination with theme park backlots. I managed a peek into one at Dreamworld, which was a little underwhelming, but I did spot some parts from the Reef Diver...