Can't use preorder money like that, its fraud. In the same way I can't sell you a computer delivered in 6 weeks and gamble it all in the mean time.
Well if or if not their pre-orders were done according to the law is one thing, but no, you can not say HOW a company uses pre-order money that specifically. If the units cost $400 to make and they took in $1200 they certainly could keep some in BTC.