Update: Android Messages app has also gotten the support for money transfers using the Google Wallet account. It can be accessed by going to the attachment panel and scrolling to down to select Send money or Request money. Like the Duo integration, it is rolling out in phases and might take some time to reach all. Also, it will not be available in select markets, where Wallet is not officially accessible.
Earlier: First sighted last month in Android Messages APK, the Duo integration is finally rolling out to the application. The Duo integration was expected to arrive in the version 2.6 of Android Messages app, but it seems it was delayed to version 2.7, which has just been released.
As you expect, even with this integration, both you and the person you want to video call from the Android Messages app need to have Duo installed and configured. You will also need to be running on Android 7.0 or above. The integration will just a shortcut in the Messaging app conversation to trigger the call. Google has a full support page explaining the feature.
At this point, it seems the Duo integration is in a staged roll-out and is being slowly enabled for the users from the server-side. It might take days before reaching all the users.
Google has also added Rich Communication Services (RCS) support for dual-SIM phones and reduced the overall size of the application. It has shed 6MB.
In more updates to Google-made applications, the search giant recently rolled out an update to its keyboard application ‘Gboard,’ which adds support for 40 more languages, stickers and performance improvements. There is no word on which exactly these newly supported languages are, expect Japanese that has been mentioned in the change-log. You can check out the full list of 120 supported languages on the Google Play Store listing to see if a language, which was earlier not supported, has been added or not.
Additionally, Google has also released the new version of YouTube Go application in the Play Store. YouTube Go is currently in beta and allows users to download or watch videos on limited data or a slow connection. There is no word on what has been changed. To remind you, YouTube Go is currently only available in India.