Apple released iOS 13.6 with a bunch of upgrades to Apple News. By stopping users from downgrading to iOS 13.5.1, it is ensuring everyone is on the latest OS with new features, and security patches.
Ios 13.6 RSS
Today, Apple released iOS 13.6, iPadOS 13.6, and all of the other minor updates that it's been testing. The big new feature is that it contains a long list of Apple News improvements.
Apple is releasing iOS 13.6 developer beta 2 today, even though the update was previously called iOS 13.5.5. It includes more granular control over automatic software updates in Settings.