You can have a client application read data from Azure Storage and load data load into a Hyperscale database (just like you can with any other database in Azure SQL Database). Polybase is currently not supported in Azure SQL Database. As an alternative to provide fast load, you can use Azure Data Factory, or use a Spark job in Azure Databricks with the Spark connector for SQL. The Spark connector to SQL supports bulk insert.
It is also possible to bulk read data from Azure Blob store using BULK INSERT or OPENROWSET: Examples of Bulk Access to Data in Azure Blob Storage.
Simple recovery or bulk logging model is not supported in Hyperscale. Full recovery model is required to provide high availability and point-in-time recovery. However, Hyperscale log architecture provides better data ingest rate compared to other Azure SQL Database service tiers.