According to the US technology media 9to5Mac reports, most of this is Apple's unintended move, will be revised soon. Unless the company gives another explanation.
It is now possible to run the latest version of iOS 11.2.2iPhone6 to iOS 10.2. Apple usually stops the registration of the old system.
Until then, Apple users could not recover iOS 10 from iOS 11.
For iPhone 7 users, this way can also be to avoid the impact of "frequency reduction door."
Some users through the SHSH service, successfully downgraded to iOS 6.1.3
IPSW.me's tracker shows that iOS 6 and iOS 7 are also registered, but users who want to revert to both systems may encounter barriers due to activation and other issues. (Think far)