That's not what happened though. His credit card didn't expire. His credit card was the Apple Card.
With any other credit card, the merchant gets their money regardless of whether the card holder pays their credit card bill on time. You can buy a MacBook Pro with a Bank of America card, default on your credit card bill, and Apple still gets paid for the MacBook Pro. That's why the money is "credit". So defaulting on your Bank of America payments doesn't make your Apple ID shut down, there's no connection. If merchants didn't get their money from credit cards, then they would stop accepting credit cards. (Merchants are already pissed about the high fees charged by the cards.)
This situation with the Apple Card is weird because the merchant and the credit card company are more or less the same company. It turns out, this is very problematic.