Now that iOS 16 has been released, Apple has confirmed that users of older iPhone models will not be able to enjoy the new battery percentage display.
In an updated support document explained Apple said the new battery indicator is not available on the iPhone XR, iPhone 11, iPhone 12 mini, and iPhone 13 mini. Apple did not explain why these devices cannot use the new feature. Apple added the battery indicator icon in an iOS 16 beta in the summer. With the new switch, which is located under Settings and Battery, users can always see their battery level directly in the status bar without having to swipe down to the Control Center.

iOS 16 battery percentage display is controversial
Since the iPhone X, users have expressed a desire to integrate the feature into iOS. But Apple's latest implementation has proven controversial. The new icon shows the battery level within the icon and not to the left of it. The white battery icon remains completely filled until the battery level is 20% or less. Then a fifth of the icon turns red and the rest of the icon becomes transparent. (Image: Apple)