Guest and External users within the tenant are automatically identified and excluded from the user synchronization process. This means they are neither provisioned nor stored in the backup system. As a result, only actual member users - those with full user accounts - are visible in both the Microsoft 365 backup Users list and in Entra ID backup.
This ensures that only relevant, fully provisioned users are included in reporting and restore operations. Guest users will not appear in any backup-related views.