Apple introduced the iOS 18 update in July and released the first beta right after the WWDC event. According to Bloomberg's report, Apple has started developing iOS 19.
Apple recently introduced new features that will come to iPhone with the iOS 18 update. iOS 18 beta 2 is in release and public beta will be released in July. While the iOS 18 beta process continues, Apple has reportedly started developing iOS 19 and even macOS 16, watchOS 12 and visionOS 3.
Mark Gurman reported that Apple has officially started working on the operating systems of 2025. While this may seem early, Gurman notes that this is the usual schedule for Apple's software development timeline. The only codenames currently known about next year's Apple software are iOS 19 (Luck), macOS 16 (Cheer), watchOS 12 (Nepali) and visionOS 3 (Discovery).
Since Apple is still testing the software with developers and enthusiasts, it may seem premature. But the usual schedule is that Apple is already developing next year's hardware and needs the accompanying software to start testing devices.