It actually sounds like some customers thought any Apple purchase would be eligible if they paid with their Apple Card, but that is not how it works – you actually need to choose the interest-free monthly installment option when buying the device.

A case of potentially misleading advertising, but also customers being dumb. I personally found the whole process quite clear with regards to how the interest-free installment plans work.

For example, that is not even an option if you try to buy an Apple device from an Apple Store outside of the US, even if you already have the Apple Card. You just get the max 3% cashback.