Interesting decision. As far as I can tell, the iPhone Upgrade Program was structured like a loan where you owned the device but kept making payments. You then had the option to trade up to a new phone and add more months to the loan, or to pay out the remainder of the loan (24 months?)

They’re discontinuing this and replacing it with Apple Upgrade, which is structured as a lease. Apple owns the device and you make payments. You either return the device or buy it out at the end.

The distinction probably doesn’t matter much to the typical consumer, other than the final price differences. Some people have an emotional attachment to knowing they own the phone instead of leasing it (I’m emotionally attached to this position, however illogical) but in the end it comes down to having a device in your hand for a monthly payment.