Google really took its time with bringing Android Wear 2.0 on the market. They started working on it pretty early in 2016, but it only came out on February 9. Its been more than two months and only a few older smartwatches models got the opportunity to update.
But now, Google listed on Android Wear support forum a list with the next batch of older models that will get updates to Android Wear 2.0. According to the post, the watches on the list will receive the Android Wear 2.0 update between the end of April and late May.
Watches that will receive Android Wear 2.0 end of April/late May
Moto 360 Gen 2
Moto 360 Sport
LG Watch Urbane 2nd Edition LTE
Huawei Watch Ladies
Asus ZenWatch 2
Asus ZenWatch 3.
All Android Wear watches announced in 2017 and forward, will receive Android Wear 2.0.