Once upon a time, I was able to get most of my communication done through Hangouts. Between its support for standard SMS, Google Voice, and normal Hangouts conversations, it was an incredibly useful tool. It could even merge SMS and Hangouts conversations into the same thread, much like iMessage on the iPhone.
Over the past year or so, Google has been separating all this functionality into standalone apps. Google started asking SMS users to switch to Messages, then removed merged conversations, and finally launched a new separate Google Voice app. The company has also been trying to move people off Hangouts itself, with its new Allo and Duo apps.
Now Google appears to be finally pulling the trigger on Hangouts' SMS integration. In an email sent out to G Suite administrators, Google said that a warning (pictured above) will appear to Hangouts users starting March 27. The email also says that SMS support will be completely removed from Hangouts on May 22.
Last year, we announced several improvements to the most popular features of Google Hangouts, such as the new video meetings experience and better group chat messaging. As part of that ongoing effort, we will be removing carrier SMS text messaging from Hangouts on Android after May 22, 2017.
Note: Google Voice numbers will continue to be supported after May 22. This change only applies to SMS text messages sent and received from carrier phone numbers.
We will prepare users for this change by showing an in-app message beginning March 27, 2017. Here is what users will see:
For SMS users on Hangouts on Android (not including Google Voice)
Users will be prompted to choose another default messaging app already installed on their phone. If none exists, they will be directed to the Google Play store to find a new SMS messaging app. Choosing a new messaging app will not impact existing SMS messages. All messages will be accessible in the new messaging app.
For SMS users using Google Voice on Hangouts on Android
Google Voice users who also send carrier SMS messages will need to choose another default messaging app. Their Google Voice messages will be unaffected and will still be available in Google Hangouts.
For Google Voice users on Hangouts on Android
Google Voice users who do not use carrier SMS text messaging will not be affected and no notification will be shown.
For non-SMS users on Hangouts on Android
No notification will be shown to users who do not have Hangouts enabled as the default SMS messenger app on their device.
What you should do
As a result of this change, you may receive questions from affected users. We've identified the users (copied below) who will be affected at your domain <snip>. You can share this Help Center article if users have any questions. If you have additional questions or need assistance, please contact G Suite support.
The G Suite Team
The message states that Google Voice users will not be affected, but with all the improvements in the standalone Voice app, you might be better off switching anyways. No changes were announced for SMS integration with Project Fi, which allows texts and calls to go through Hangouts, but I'm almost certain that it will stay (at least as long as Voice integration does).