Zeugma, Apple normally supports iOS devices with iOS updates for five years after introduction. Unfortunately, your iPhone 6 was released on September 9, 2014 so your five years were up on Monday. I am pretty certain it will not be supported for the iOS 13 update when it is released next week. The reason is not due to Apple locking it out, but rather the older hardware will be incapable of taking the update due to lack of hardware functions the new iOS requires.
Yup, I just searched the answer and this is what I found for you:
“But, there's bad news for those who are still on older versions of the iPhone. The iOS 13 system is leaving out certain iPhone models, meaning the iPhone 5S, iPhone 6, and iPhone 6 Plus won't be supported. In fact, the oldest devices that will support the new operating system are the iPhone SE, 6S, and 6S Plus. If you've got one of these, you're in the clear for the iOS 13 update. If you're sporting an iPhone 6, you'll want to take note of the unfortunate fact that your device won't be able to use the new operating system.
If you're still using your iPhone 6, rest assured that your device will still work, but you won't be able to get the new overhaul that Apple is releasing. If you've got no problem with that, then keep rockin' that iPhone 6 in style. — Elite Style
Thanks Sword. I couldn’t find that on the Apple site. I knew you’d know where to find it! I’ll take a look at the new models, but will most likely stay with my 6 for another year or two. The battery is only a bit more than a year old.