Back in February this year, Asus said Android Wear 2.0 forthe Zenwatch 2/3 will arrive in early Q2.
Then, in mid-May, Asus UKsaid in a tweet that the Android Wear 2.0 update has started rolling out. However, that turned out to be untrue - the tweet was deleted and the company clarified that the update will arrive towards the end of the month. That also didn't happen.
Then, in the second half of June, Asus Germany said the update will start rolling out to the Zenwatch 2 in July, while the Zenwatch 3 will get it in August. This was followed by a tweet from Asus US, which said the Zenwatch 3 will start getting the update in the coming weeks. That tweet has also been deleted.
So currently, it's difficult to say when exactly the roll out would begin, and which wearable will get the update first. Let's hope the update arrives sooner than later.