The title is misleading at best. Apple does not care what support you have. They just don't want you to advertise that in their app store.
It is a tool for controlling the behavior of both users and developers by using their control of an unrelated platform.
Users find apps for their iPhone on the App Store. There are no other app stores for the iPhone. Users do not visit an app's web page before they install it.
Users will not find anything when they search the app store for e.g. "navigation app with pebble support". Users will not see Pebble support listed as a feature when they compare two apps.
Developers know from the above that they won't gain any appreciable number of users by adding Pebble support.
In that light I don't see much difference between banning mentioning a feature and banning the feature itself.
You can search Google.
Fascist? Yes. Surprising? No. New? Certainly not.
Apple saying you can't advertise other versions of your product is slightly dickish but totally understandable. Apple saying you can't advertise features of your iOS app because they happen to involve competing products is completely unreasonable.
From a consumer perspective, I can see Apple's argument that mentioning Android support doesn't matter because the app running on Android has no bearing on whether it works on your iOS device or not.
But for something like a wearable, that's absolutely information I want as a consumer. To me, it's much closer to an app being able to say whether they support BTLE heart rate monitors or not. It's something that interfaces directly with the device.
I suspect the actual reason Apple is suddenly expanding what it considers a mobile platform is that it's a preemptive strike against Android Wear support for iOS.