This is not a major new capability but still interesting as it gives you more control, you can now define the name of the resource group being used by Azure Recovery Services to store the instant recovery point.
Previously, the resource group was hardcoded and looked like AzureBackupRG_<geographical location>_<number>.
You can still let Azure use this hardcoded name.
If you want to define the resource group name, logon to your Azure portal (https://portal.azure.com/) and access your Recovery Vault to either edit or create backup policies
Then access the Backup Policies blade (available in the Manage section) and edit the existing policy/ies (or create a new one) and define the naming convention with the Azure Backup Resource Group field