An official support page confirms that the distribution of the update will start shortly (within a few days). Keep in mind that this is the update of the Android Wear app and not a smartphone software update distributed via OTA.
In the meantime, it is possible to download both the new version via APK Mirror:
Android Wear has recently crossed the milestone of version 2.8, in distribution for a few days, but Google, announcing the availability of the new SDK 2.2.0, has already started to make known some features that will be introduced by the next release 2.9.
⚡ New Wear SDK 2.2.0 + final Android Wear Oreo emulator
✅ New unread notification indicator (on by default)
✅ ComplicationDrawable now handles permission
✅ New Callback indicates if ComplicationDrawable completed loading images/icons
More details ↓ https://t.co/pZXk8HczBi
— Android Developers (@AndroidDev) January 25, 2018
Also, the next step in the development of the wearable platforms of Google will not upset the user experience, limiting itself to making useful refinements.
The end user, in particular, can benefit from the new counter of unread notifications. By default, a white colored indicator will be shown at the bottom of the watch face (bottom left figure).
Developers will be able to modify the accent color, to better integrate the counter with the watch face graphics, or completely deactivate the indicator, replacing it with (figure in the middle at the bottom) the second type of counter positioned at the top of the screen, or (figure right below) in another position that will be the same developer to establish.
The 2.2.0 version of the SDK includes the final version of the Oreo-based emulator and brings with it an improvement to the ComplicationDrawable class.
In this case, it is a novelty that will mainly benefit developers: starting from version 2.9 the complications will automatically ask for permissions when they are selected by the settings – without the need to enter the custom code – and a new feature will be introduced to load more complicated complications containing images or an icon.
Interested developers can find more details in the link in SOURCE.