Azure Blob Storage Cold Tier was generally available since Aug 10th, 2023. It is a new online access tier that is the most cost-effective Azure Blob offering for storing infrequently accessed data with long-term retention requirements, while providing instant access.
Azure Storage Service Level Agreements (SLA) describe Microsoft’s commitments for uptime and connectivity for Azure Storage services. The SLA now includes Azure Blob Storage Cold Tier.
Refer to the Service Level Agreements (SLA) for Online Services for additional details.