Why pre-order? These things can't be difficult to make - once they have made one - they can make zillions. Pre-order queues are only their for the companies' benefit:
1) Cash in the bank to fund development (plus interest)
2) To judge customer demand
And of course if its a scam, its just a way of taking people's money, never to be seen again. Not saying these are, just a fair % of bitcoin services have been scams.
I'd love a hardware wallet, don't get me wrong. But I'll buy mine when they are available and have been reviewed by peers. Customers gain nothing from pre-ordering, you are just risking your own capital for no reward.
If they wanted to reward customers that pre-order, they would offer incentives such as a discount or "limited edition" for first 100 orders.
Preoder money in a hardware project makes sense to be used for the setup of the production line. Creating the first production line is a very expensive process and a factory has to be adapted to start producing the hardware only once the factory is ready it's very cheap, as you said, to produce zillions.
Preordering in BTC has proven to be a bad choice for the consumer, I consider this kind of preordering more like a donation...