An admin control feature which enables you to set unthreaded room history behaviour separately from 1:1 and group conversation. Which means the default history state can be turned on or off by administrators. They can also discourage users from modifying the unthreaded rooms' default history setting. Also note that this setting has no effect on threaded rooms. The history of the threaded room is still on.
These additional features give you greater power and flexibility when it comes to setting chat history options for non-threaded rooms. This feature is enabled only for the organizations who use chat, the organizations who use classic hangouts will not get impacted.
The feature will be on by default for admins.