With WWDC 2023 just two months away, all eyes will be on the debut of Apple's long-rumored VR/AR headset, but the real dark horse of the event may be changes to watchOS, the company's wearable OS.

Bloomberg's well-connected reporter Mark Gurman claims in the latest issue of his Power On newsletter (opens in new tab) that an upgrade to watchOS 10 could result in major interface changes.

"The new watchOS should be a fairly major upgrade, and I think it will make some notable changes to the user interface," he writes.

This is in contrast to iOS 17, the iPhone OS, which appears to be a more modest quality-of-life improvement.

Garman does not elaborate on what to expect from these UI changes, but the very fact that Apple is planning something in this area is significant. Previous watchOS upgrades have introduced new watch faces and tweaked the way owners interact with their devices, but nothing dramatic.

However, Garman is very clear about why Apple is now considering a rework of the OS: given the lack of major hardware updates for the Apple Watch, he writes, it is "important" that watchOS make significant progress.

That's unfortunate, but not surprising: with just over four months until the iPhone 15 and Apple Watch Series 9 launch, leaks and rumors about the latter are virtually nonexistent, suggesting that it will look nearly identical and have few new features.

Indeed, significant changes to Apple's wearable product line appear to be planned for next year, with reports that the 2024 Apple Watch Ultra 2 will benefit from a micro-LED screen and grow to 2.1 inches.

The big question about watchOS 10's "fairly extensive upgrade" is what it means for compatibility. watchOS 9 saw Apple finally end support for the venerable Watch Series 3, but the significant shift in UI, especially CPU-intensive, could bring a similar end to the Apple Watch Series 4 and the first-generation Apple Watch SE.

We will find out soon enough. Apple has announced that WWDC 2023 will kick off on Monday, June 5, so we will see the new interface for the first time then.