HostNameInCertificate changes in Azure SQL Managed Instance affecting client connectivity

Azure SQL Managed Instance is changing how TLS certificates are stored and handled in managed instances. One of those certificates was specifically tailored to support migration scenarios where SQL clients retain the server name, while updating its record in DNS so that it resolves to the managed instance instead. This was supported with an instance certificate that we are now replacing in favor of a more complete solution. When does this change take effect? New managed instances already contain certificates with a reduced list of SANs. Existing managed instances will have their certificates r