The days of Google Talk are over
So if you are currently using what Google now calls the “classic Hangouts” app as your SMS client, Google will ask you to switch to Android Messages (unless you use Google Voice with Hangouts for Google Voice SMS, or you are a Project Fi user).
So if you are currently using what Google now calls the “classic Hangouts” app as your SMS client, Google will ask you to switch to Android Messages (unless you use Google Voice with Hangouts for Google Voice SMS, or you are a Project Fi user).