Users on iOS 10 in multiple countries are sharing the new additions within Tips, which allows Apple to prepare those on the current version of iOS for the impending launch of iOS 11. Looking back at previous release schedules for iOS versions, Apple typically launches the new iOS to the public about one week after its fall iPhone event, and two days before the debut of the new iPhone devices, with a few exceptions.
2012: Event Sept 12 / iOS 6 releases Sept 19 / iPhone 5 released Sept 21
2013: Event Sept 10 / iOS 7 released Sept 18 / iPhone 5s released Sept 20
2014: Event Sept 9 / iOS 8 released Sept 17 / iPhone 6 released Sept 19
2015: Event Sept 9 / iOS 9 released Sept 16 / iPhone 6s released Sept 25
2016: Event Sept 7 /iOS 10 release Sept 13 / iPhone 7 released Sept 16
This year, the iPhone event is on September 12, while the so-called iPhone 8, iPhone 7s, and iPhone 7s Plus are predicted to debut on September 22. This would place the official public release of iOS 11 around September 20, although Apple could decide to release iOS 11 a bit earlier ahead of the iPhone launch, like it did in 2015 and to a lesser extent in 2016.