Buzz
Presently, after upgrading your device to iOS 10.2.1 for new experiences, Apple has promptly disallowed downgrading to iOS 10.2 for iPhones and iPads. This step is taken to prevent unfortunate mishaps for users and to curb the unlocking of devices, which is currently under significant scrutiny without official confirmation.
Apple does not permit downgrading iPhones and iPads to iOS 10.2.
While experiencing the new features on iOS 10.2.1 enhances user experience, downgrading to iOS 10.2 afterward allows your device to operate more smoothly with previous iOS 10 upgrades once you've explored the new features and discovered what's new on iOS 10.2.1.
However, currently, we cannot downgrade to iOS 10.2.1 anymore as Apple does not allow downgrading iPhones and iPads to iOS 10.2 or previous iOS 10 versions. This measure aims to enhance the security of the iOS operating system and prevent errors during user usage.
https://Mytour.vn/apple-does-not-allow-iphone-ipad-downgrade-ios-102-18198n.aspx
If you haven't upgraded to iOS 10.2.1 yet, Apple's restriction on downgrading iPhones and iPads to iOS 10.2 won't affect the usage of your devices. Additionally, to check the status of Firmware iOS being locked or Apple's disallowance of downgrading to certain iOS versions, you can refer to the article on checking Firmware signing status for iPhone, iPad to gather information and avoid errors during the downgrade process.
