Well, what's this hidden in the watchOS 4.3.1 beta? As spotted by 9to5Mac, it's a reference to a "3rd party face config bundle", which sounds very much like Apple is about to open up the device to developers who fancy having a go at making their own watch faces.
Unlike Wear OS (née Android Wear), watchOS has never supported third-party watch faces, ever since the first Apple Watch came out in 2015. One of the benefits of owning a smartwatch is you can change the face whenever you like, but up until now your only choices on the Apple Watch have been those made by Apple.
Admittedly, some of those watch faces are very nice indeed. But letting other developers in on the act would no doubt see an explosion in the number of watch faces available – just about every taste and style would eventually be catered for. Probably.
Nothing official yet
This is obviously just a telling bit of code and nothing more for the time being. Apple hasn't said anything about the change, or when it might go live, and probably won't for a while: the WWDC developers conference in June is a good bet for an announcement on the next batch of watchOS updates.
With Google rebranding its own wearable platform and cheaper alternatives like the Fitbit Versa hitting the market, Apple must be feeling the pressure to stay on top of its game in the wearables department. Dedicated Apple Watch apps are pretty thin on the ground, so this could help give the device a shot in the arm.
Of course, as Wear OS shows, letting third-party developers make their own watch faces would lead to a lot of so-so designs as well as a lot of appealing ones, but presumably Apple would put some kind of screening system in place like it does with full apps.