You can add all users to a OneDrive for Business app so that all users, including new users that are automatically discovered, are included in backups of the app.
From the navigation pane, go to Protect > Applications > Office 365.
The Office 365 apps page appears.
In the Name column, click the app to add all users to.
The app page appears.
On the Content tab, click Add, and then click All users.
The Enable group dialog box appears.
From the Office 365 plan list, select the plan to use for users.
The next time the OneDrive for Business app is backed up, new users are automatically discovered and included in the backup.