The “waitlist” is not a reservation list to reserve your miner or spot in line. When applying for the wait list you are essentially on a list to get direct notifications for when the inventory is updated on the website for that particular product.  When an order is cancelled or payment time expires, it will automatically add inventory back to the website and will notify people on the waitlist. If you visit the site and it shows out of stock after receiving notification, then they have already sold out again.