Apple announced WWDC25 earlier this week, taking place on June 9th. That means were just around the corner from seeing all of Apples annual software upgrades, including iOS 19, iPadOS 19, macOS 16, visionOS 3, tvOS 19, watchOS 12, and possibly even more.iOS 19 is anticipated to receive a massive overhaul this year, bringing a fresh coat of paint to the operating system. However, here well be focusing on Apples second round of AI features coming to iPhone.Trio of delayed Siri features from iOS 18.4First things first, iOS 19 will likely introduce the three major Siri upgrades that the company announced at WWDC24. These features were supposed to release as part of iOS 18.4 this spring, but the company announced that it would need more time to work on it.Those three features are: personal context, on-screen awareness, and taking action in apps.This trio of features wouldve allowed Siri to better understand who you are, see what youre doing on your phone while youre talking to it, and taking actions on your behalf. It wouldve made Siri into an all-encompassing digital assistant that many people dreamed of.Apple didnt provide much of a specific timeline when it delayed these already-announced Siri features. It said that theyd roll out in the coming year, so its unclear whether or not thisll be part of iOS 19 or iOS 19.1 later this fall, or if itll roll into a winter or spring release. Only time will tell.LLM SiriBloombergs Mark Gurman reported last year that Apple was working on a new Siri backend for iOS 19 which he referred to as LLM Siri. This was supposed to be accompanied by a new conversational Siri interface, though that part is reportedly delayed until iOS 20.However, the new LLM Siri backend is still launching as part of iOS 19, and will be fundamental to allowing the aforementioned three iOS 18.4 features to come to life. From Gurmans Power On newsletter:In order to get Apple Intelligence out the door as part of iOS 18, the company didnt have time to meld the two systems together. That means the software doesnt work as smoothly as it could.For iOS 19, Apples plan is to merge both systems together and roll out a new Siri architecture. I expect this to be introduced as early as Apples Worldwide Developers Conference in June of this year with a launch by spring 2026 as part of iOS 19.4. The new system, dubbed LLM Siri internally, was supposed to also introduce amore conversational approachin the same release. But that is now running behind as well and wont be unveiled in June.With this new LLM Siri backend, Apple will finally achieve a unified Siri system, one thatll hopefully be easier to build on top of in the future. For context, Siri currently taps two different backends when making requests: a legacy one for simple tasks, and a modern one for more complex requests.The launch of LLM Siri wont have an immediate benefit to the end-user in terms of brand-new features, at least until iOS 20 when the conversational aspect of it launches.Expansion across appsApple will also reportedly be expanding some of its already-released Apple Intelligence features to more apps. This likely means well see Image Playground, Genmoji, and Apples summarization features in more places, per Bloomberg:The bad news is that Apple is unlikely to unveil groundbreaking new AI features at this coming WWDC. Instead, it will likely lay out plans for bringing current capabilities to more apps.This also means Apple probably wont introduce any fundamentally new Apple Intelligence capabilities in iOS 19, beyond what it has already announced.My favorite Apple accessories on Amazon:Follow Michael:X/Twitter,Bluesky,InstagramAdd 9to5Mac to your Google News feed. FTC: We use income earning auto affiliate links. More.Youre reading 9to5Mac experts who break news about Apple and its surrounding ecosystem, day after day. Be sure to check out our homepage for all the latest news, and follow 9to5Mac on Twitter, Facebook, and LinkedIn to stay in the loop. Dont know where to start? Check out our exclusive stories, reviews, how-tos, and subscribe to our YouTube channel