Update migrate.md

We're adding the information "A rollback to the old environment will not be possible." at the end of the FAQ question: "What happens to my old App Service Environment?"

Author: auolivei

articles/app-service/environment/migrate.md

@@ -149,7 +149,7 @@ There's no cost to migrate your App Service Environment. You'll stop being charg
 - **What happens if migration fails or there is an unexpected issue during the migration?**  
   If there's an unexpected issue, support teams will be on hand. It's recommended to migrate dev environments before touching any production environments.
 - **What happens to my old App Service Environment?**  
-  If you decide to migrate an App Service Environment, the old environment gets shut down and deleted and all of your apps are migrated to a new environment. Your old environment will no longer be accessible.
+  If you decide to migrate an App Service Environment, the old environment gets shut down and deleted and all of your apps are migrated to a new environment. Your old environment will no longer be accessible. A rollback to the old environment will not be possible.
 - **What will happen to my App Service Environment v1/v2 resources after 31 August 2024?**  
   After 31 August 2024, if you haven't migrated to App Service Environment v3, your App Service Environment v1/v2s and the apps deployed in them will no longer be available. App Service Environment v1/v2 is hosted on App Service scale units running on [Cloud Services (classic)](../../cloud-services/cloud-services-choose-me.md) architecture that will be [retired on 31 August 2024](https://azure.microsoft.com/updates/cloud-services-retirement-announcement/). Because of this, [App Service Environment v1/v2 will no longer be available after that date](https://azure.microsoft.com/updates/app-service-environment-v1-and-v2-retirement-announcement/). Migrate to App Service Environment v3 to keep your apps running or save or back up any resources or data that you need to maintain.
 
@@ -165,4 +165,4 @@ There's no cost to migrate your App Service Environment. You'll stop being charg
 > [App Service Environment v3 Networking](networking.md)
 
 > [!div class="nextstepaction"]
-> [Using an App Service Environment v3](using.md)
+> [Using an App Service Environment v3](using.md)