In October, the game will cease support for multiple kinds of device and operating systems, locking some players out of the game. On Twitter, the official Pokemon Go account has announced an end to support for devices running Android 5, iOS 10, and iOS 11 in October. This could mean that the app will roll out new features that would be difficult to support on older devices.
In an upcoming update to Pokémon GO in October, we will end support for Android 5, iOS 10, and iOS 11, as well as iPhone 5s and iPhone 6 devices. Trainers with devices not specifically listed here will not be affected and don’t need to take any action.
— Pokémon GO (@PokemonGoApp) August 31, 2020