[DigitalToday reporter Jinju Hong] Apple is expected to unveil watchOS 27 at WWDC next week and overhaul Apple Watch health features and the overall user experience.

According to IT outlet 9to5Mac on June 1, key changes discussed for the update include improved heart-rate tracking, a high blood pressure alert feature, new watch faces and Siri performance upgrades.

The most notable area is health features. Bloomberg's Mark Gurman mentioned that watchOS 27 will improve the Apple Watch's heart-rate tracking. Details were not disclosed, but it has been discussed that the feature could be supported on current Apple Watch hardware on sale. There is also speculation that the Apple Watch Ultra 4 could add a large number of new health sensors, leaving open the possibility that Apple could expand health features by differentiating between existing and next-generation products.

Blood-pressure-related features are also drawing attention ahead of the event. According to a recent report, a new high blood pressure alert feature is said to be under review by the U.S. Food and Drug Administration (FDA). The outlet said it is highly likely the feature will be included in watchOS 27. If it is released, Apple Watch health management would extend beyond heart-rate and activity tracking into alerts for abnormal blood pressure signals.

On the display side, a new watch face is expected. watchOS has introduced new watch faces each year with new versions, and this time a simplified version based on the Modular Ultra design has been raised as a possibility. Gurman described Modular Ultra as "my favorite watch face design Apple has ever made" and said he had hoped it could be used on Series models as well as Ultra models. He added he was curious what form the new watch face would take. Attention is on whether the information-dense layout, close to Ultra-only, will be expanded to regular Series models.

Siri improvements are also cited as a major change in watchOS 27. Apple's new Siri is expected to see bigger changes in iOS 27, iPadOS 27 and macOS 27, but Apple Watch users may also benefit. It is not known whether watchOS will add a standalone Siri app like the iPhone. Still, the focus has been described as enabling responses to more complex requests and improving overall reliability versus now. If the voice assistant becomes more accurate and expands what it can handle, the utility of the wrist-worn Apple Watch could also rise.

watchOS 27 is more likely to focus on stabilisation and incremental improvements than on sweeping design changes. Bloomberg reported the update would "primarily focus on stability, performance, and minor improvements." That suggests the emphasis may be on improving the completeness of existing features rather than the number of new features.

That narrows the main points to watch in the announcement into two tracks. One is how far health features will actually expand, and the other is how perceptible changes will be to everyday-use elements such as Siri and watch faces. Not much has been disclosed so far, but the possibility remains that Apple will unveil additional features on the WWDC stage.