Note point 4.2.4
https://developer.apple.com/app-store/review/guidelines/#minimum-functionality
- 4.2.4 Apple Watch apps that appear to be a watch face are confusing, because people will expect them to work with device features such as swipes, notifications, and third party complications. Creative ways of expressing time as an app interface is great (say, a tide clock for surfers), but if your app comes too close to resembling a watch face, we will reject it.
These aren’t going via the App Store, you just install it on your personal watch.
So the developer guidelines don’t really apply.