Correct! They are separate, but of course if you are still on the hook for an existing phone then you would need to pay up!While this is true, you will not be able to trade in your ATT NEXT phone and will you are still on the hook to pay off the remainder of your ATT NEXT commitment. So, you can have a second phone (with installment plan) through the Apply Upgrade Program, but you cannot replace your ATT NEXT installment contract with the Apple Upgrade Program.
Meanwhile, I'll be selling my 6+ that I purchased subsidized 1 year ago and go with the Apple Plan