After many years of using Hangouts as its main online chat platform, Google has begun gradually replacing it with Google Chat. Last week, video calls are over of Hangouts, and now, the Mountain View giant announced in a post that later this week (3/12), it will be possible to see your Hangouts group conversations in Chat.
This content migration is part of the current implementation phase of the tool, which will be available for most paid plans for companies and corporate professionals. In addition to receiving group conversations from Hangouts, the tool will also allow users to add and change members of the conversation group.
Whenever a new user is added, group members will be notified. In addition, the new member will have access to messages exchanged in Google Chat, including those sent before they were added to the group. They will also be able to see any pinned messages in the conversation.

Google Chat conversation screen. Image: Reproduction
It's worth mentioning that the rollout of group chats from Hangouts to Google Chat will be gradual. In other words, don't be surprised if you still can't see the messages on December 3rd. The migration of messages will continue over the following weeks, so you'll just have to wait a few more days.
Another feature mentioned is the change in the retention policies for conversation history. In other words, users and administrators will be able to choose how long Google Chat keeps conversation histories, deleting them after the deadline.
Google Chat is currently not available to users of the free tools, who will still be using its predecessor. Google's plan is to create a free version of Google Chat and close Hangouts by the first half of 2021, migrating it completely to the new app. In fact, this is why It is no longer possible to have video conversations via Google Hangouts.
Through which channels you reach those people, classic and out of the box. XDA Developers.