Merge pull request #276574 from dominicbetts/aio-update-note

AIO: Add update note

Author: prmerger-automator[bot]

articles/iot-operations/get-started/overview-iot-operations.md

@@ -41,7 +41,10 @@ There are two core elements in the Azure IoT Operations Preview architecture:
 
 Azure IoT Operations runs on Arc-enabled Kubernetes clusters on the edge. You can deploy Azure IoT Operations by using the Azure portal or the Azure CLI.
 
-[Azure IoT Orchestrator Preview](../deploy-custom/overview-orchestrator.md) manages the deployment, configuration, and update of the Azure IoT Operations components that run on your Arc-enabled Kubernetes cluster.
+[Azure IoT Orchestrator Preview](../deploy-custom/overview-orchestrator.md) manages the deployment and configuration of the Azure IoT Operations components that run on your Arc-enabled Kubernetes cluster.
+
+> [!NOTE]
+> During public preview, there's no support for upgrading an existing Azure IoT Operations deployment to a newer version. Instead, remove Azure IoT Operations from your cluster and then deploy the latest version.
 
 ## Manage devices and assets