Pre-ordering didn't involve transfer of funds.
The preorder process simply involved giving name, address, and quantity. Then they would whip up an escrow agreement and a deposit would be held in escrow. That second part hasn't taken place, so nobody needs to do a chargeback.
My absolute best guess is that if someone did pre-order they have allready done a chargeback(hopefully they paid with some form of chargeback capable method)