Explanation :
The statement is definitely true.
Usually, when Microsoft releases a new service, the service is released in private preview phase. During private preview, Microsoft will invite a few customers to test the new service and provide feedback. Also during private preview phase, regular support services are not available.
When the service is mature and considered ready for production environments testin, Microsoft will transition the service to public preview phase. During this phase, any customer can run and test the service. As opposed to private preview, Microsoft teams will provide formal support services in this phase.
The last step is migrating the service to generally available (GA) phase. During public preview phase, there may be functionalities or features fixing as well, but once the service is transitioned to GA, the new service is considered stable and ready for real production workloads. Also, the service is covered by support via all official Microsoft support channels.
And now, coming back to the statement presented in this scenario, we can clearly state that public preview services are available to all Azure customers. Also, services in public preview phase are marked accordingly in the Azure portal, having a “Preview” label attached to the their name.