Apple Confirms watchOS 27’s Biggest Compatibility Cutoff Ever as Five Models Lose Siri AI

Apple confirmed that watchOS 27 will only support Apple Watch Series 9 and later, Apple Watch Ultra 2 and later, and the upcoming Apple Watch SE 3.

Owners of the Apple Watch Series 6, Series 7, Series 8, second-generation Apple Watch SE, and the original Apple Watch Ultra are losing support.

Apple rarely makes cuts this aggressive, making the original Apple Watch Ultra’s exclusion particularly surprising given expectations of a longer support lifespan.

The cutoff is not routine pruning of older hardware. It reflects how deeply Apple has integrated Siri AI into watchOS 27, a feature unveiled alongside iOS 27 and macOS Golden Gate at WWDC 2026.

Why Siri AI Needs a Chip the Old Watches Don’t Have

The marquee feature in this year’s watchOS release is support for Siri AI, which will undoubtedly require the more powerful chips used in the latest Apple Watch models. 

The Apple Watch Series 9 became the first model to support on-device Siri processing when it introduced the S9 chip as the first to include a built-in Neural Engine. 

Siri AI requires both a supported Apple Watch and a nearby Apple Intelligence-enabled iPhone, with support beginning on Apple Watch Series 9. 

This follows the same hardware gating Apple applied across iOS 27. Siri AI runs locally wherever possible, requiring a Neural Engine powerful enough for context-aware AI without lag.

The S6, S7, and S8 chips were never designed for that workload because Apple Intelligence did not exist when they were developed.

What Apple Actually Said When Pressed

In an interview with TechRadar’s Matt Evans, David Clark, Apple’s senior director of watchOS software engineering, and Cait Dooley, head of Apple Watch and Health Product Marketing, said the goal was to make Apple Watch “a true co-partner to Apple Intelligence.”

“We really wanted to make sure the Siri experience is singular and consistent, whether I decide to ask Siri on my wrist a question, or whether I have my phone in my hand and I decide to interact with Siri there. We really wanted to feel like it’s one Siri, that has access to your data and can personalize it consistently.”

Clark cited using Apple Watch in a grocery store to pull up a recipe’s ingredient list hands-free, a use case that depends on the watch understanding context itself, keeping it unpaired from the iPhone.

Dooley added: “With every software release across every single one of our platforms, we always want to ensure that you have the best experience, so we make power and performance a priority.”

What Happens to the Older Watches Now

There is at least some good news if you’re still using an older Apple Watch: it should keep getting security updates, and it should still work with the latest iPhone software. 

If your watch appears on the supported list, you can expect the complete watchOS 27 experience, including Siri AI, when the update rolls out to everyone this fall. 

For anyone weighing whether to upgrade ahead of that rollout, the calculus is now straightforward: five models, some barely three years old, will be functionally frozen at their current feature set indefinitely. 

While the Series 9 and newer continue receiving the AI capabilities, Apple is building its entire wearable strategy around going forward. 

Source: ‘It’s the most convenient way to interact with Siri’