This update was released for the few devices that don't support iOS 15. We don't expect Apple to continue to be compatible with iOS 12 for much longer. Apple considers these phones to be old. The iPhone 6 is sure to remain in the memory of many Apple users, as it was the company's first smartphone with a considerably larger screen than its predecessors. The phone was discontinued a few years ago, but it's still receiving security patches and technical support from Apple, perhaps not for much longer.
Apple has now added the iPhone 6 to its “old products” list. Strangely enough, the larger iPhone 6 Plus was already considered a vintage product before the iPhone 6.This is because Apple continued to sell the 4.7-inch iPhone 6 for a longer time in some regions after permanently discontinuing the iPhone 6 Plus.