Leveraging Android Wear
In the article you expressed surprise that it leverages Android Wear for some things and speculated that Google may view Pebble as a fallback technology.
No, the reason that Pebble leverages this API is because that API is open to be leveraged. Apple is not open and free about leveraging their proprietary APIs. Google views things differently and lots of programs that are not Android Wear devices, leverage the Android Wear APIs.
In the end, Google is just a friendlier and more platform for 3rd parties.