https://www.theregister.co.uk/2018/03/16/android_wear_becomes_wear_os_from_google/

LogoWatch LogoWatch Google’s re-branded Android Wear, the cut of Android for wearable devices, as “Wear OS by Google” and added the tag line "make every minute matter".

The company’s brief announcement doesn’t really explain why Google’s made the change, other than to say it’s “a new name that better reflects our technology, vision, and most important of all—the people who wear our watches.”