Yes, Databricks now creates a default Unity Catalog (UC) metastore and its corresponding storage account if none is specified during setup. The default storage account for the metastore is hosted and managed by Databricks within its own Azure tenant. While the storage is secure and isolated, it may not meet the specific compliance requirements of your organization.

If your organization requires all data to remain within its Azure tenant and mandates control over all storage accounts, including monitoring and access management, you can provide your own storage account credentials when creating the metastore.

However, you cannot update the existing storage account in a metastore to a different one. To use a new storage account, you will need to create a new metastore configured with the desired storage account.