https://www.gamespot.com/articles/snes-classic-edition-pre-order-guide-tracking-amaz/1100-6451207/

August 25 update 2: The SNES Classic Edition is back in stock at Walmart right now. It likely won't last long, so be sure to jump on it quickly if you're interested. This may be one of the last opportunities to pre-order the system prior to its launch in late September.

August 25: A number of Amazon pre-order customers have been notified that they may not receive their order on time. It's unclear how long the hold-up will last or what the problem is, but affected users have been sent an email notifying them of the potential delay. The retailer states that everyone who pre-ordered the system will eventually get their hands on one.