I’ve got a 2023 Mac Studio M2, and was dismayed by the M3 & later. So I’ve been trying to track down more details. That specific device list is only for:

> Apple’s most powerful on-device model and the features it enables, like expressive voices and more advanced dictation, […]

On other devices, I think there’s still on device support (just not with the “most powerful model”), for these devices:

> Apple Intelligence and Siri AI in iOS 27, iPadOS 27, macOS 27, watchOS 27, and visionOS 27 are available on iPhone 16 models or later, iPhone 15 Pro, iPhone 15 Pro Max, iPad mini (A17 Pro), MacBook Neo (A18 Pro), iPad models with M1 or later, Mac with M1 or later, Apple Vision Pro, Apple Watch Series 9 or later, Apple Watch Ultra 2 or later, and Apple Watch SE 3 when paired with an Apple Intelligence-enabled iPhone nearby.

This is from the footnotes on https://www.apple.com/newsroom/2026/06/apple-introduces-siri...

I do wish they’d been more clear about what the “advanced features” are :(