Apple is encountering significant challenges in the development of its AI-based platform, Apple Intelligence, and its enhanced virtual assistant, Siri. The company first introduced Apple Intelligence during WWDC 2024 but has yet to deliver on its promises. Furthermore, Mark Gurman reported that the improved Siri will not be included in the iOS 26.4 update later this year due to issues arising during internal testing.

However, this report was based on internal communications from an Apple employee. In response to inquiries from CNBC, a company executive provided a reassuring statement confirming that the project is "still on track to launch in 2026."
We tend to trust statements from high-ranking executives over speculative rumors. Although the timeline of 2026 may seem broad, it is reasonable to anticipate that the Siri update will be released after iOS 26.4, likely coinciding with the launch of the iPhone 18 series.
Additionally, we recently reported on Apple’s change of direction concerning the AI-powered Health+ service, which has been postponed in favor of gradually releasing individual features integrated into the existing Apple Health application. This shift implies that internal restructuring may be contributing to the delays we are observing.
Source