Congrats! Happy to know you got the license refunded/effectively transferred, and thank you for sharing that information. It is only fair for them to do that because you must have only gotten the 6015 not long ago.
Now that you mentioned firmware updates, I was surprised to see an update notice popped up on my screen for my AVR-X4400H. That thing was launched in 2017, so 5 years later Denon still release an update for it, can't really complain..