If Liz make a preorder list, with payments, maybe the server will not hog… maybe I can be the 1st one on the list
It doesn't work like that!
The moment they go on sale in any form, lots of people will try to purchase them – whether as a pre-order or for immediate shipment. So it just moves the expected heavy server load from "later" to "now".
Pre-orders are useful when cashflow is a problem – if you need $100,000 to make 10,000 widgets and you don't have the hundred grand, pre-orders may help get you that cash to make the widgets, by either by convincing a bank to lend it, or collecting the money from the customers as a deposit or paid-up-front.
Both approaches have notable risk – manufacturing delays could mean that you end up borrowing the money for too long, or holding customers money for longer than promised.
There have been several "vapourware" projects where preorders were taken, either with or without payment, and for whatever reason the widget was never made.
As the Foundation aren't worried about cashflow, they (and us) gain nothing by taking pre-orders except the headache of handling it.