Or maybe if they have a 6 and want a CPU upgrade of 3X and GPU upgrade of 6X or maybe want 2-3 X the RAM for more seamless multi-tasking, or possibly the dramatically higher quality camera, or ..... or .....
I mean seriously! if changing the look of the phone is all that matters to you, yes the repositioning of the antenna lines probably will not float you boat. But I upgrade for features and performance and we still know very little about those except what we get from history and that is about 50-100% faster CPU and 100-200% faster GPU each year. So if you are sporting an A8 the A10 will probably rock your world! With additional memory, faster wireless and who know what else, there is still a lot this phone could do.
Oh ya! and I can give you one more we don't yet know about.
If the base model is 32gb and someone upgraded to 64gb last year but didn't need it. Upgrading this year on one of the more common lease plans would actually reduce their monthly cost and give them a new phone.