In fairness, this was a relatively lackluster update to the iPhone. There is little difference between the iPhones 11 to 15 for normal consumers. It suggests upgrade cycles can lengthen as a result.

If you buy the iPhone 11 right now, you will get 1 version update and that's it. You will still get security updates I guess.

Where has it been stated that iPhone 11 will only get one more (presumably iOS 17?) update?

Nowhere. The release of iOS 17 will support iPhone XR/XS, which is one generation older than iPhone 11. GP probably means iPhone 11 will get iOS 18 next year and no more OS upgrades after that (based on the fact that iPhone X is not getting iOS 17, iPhone XS may not get iOS 18, and so on).

While Apple does not guarantee or publish a guarantee about how many years of major OS versions and security updates iPhones will get, it’s typically been about six or seven years of major OS version upgrades (from original device release) and another two or more years of security updates. The iPhone 11 was released in 2019 with iOS 13. When it’ll stop getting a new iOS version is up to Apple.

> There is little difference between the iPhones 11 to 15 for normal consumers.

Nope. The improvements in camera and what it offers are noticeable, especially for low light photography as well as video quality and types. Some examples: night mode, portrait mode, cinematic mode, etc. Normal customers do care for or are impressed such things. The difference from one year’s phone to the next year’s may or may not be significant, but if you’re looking from iPhone 11 to iPhone 15, there is a really huge difference.