updated messaging (#5105)

Author: Abdallah Shaban

src/fragments/lib/auth/js/overview.mdx

@@ -15,7 +15,7 @@ Authorization is often done in one of two ways:
 1. Clients pass the tokens to the backend that perform custom logic to allow or deny actions
 1. Clients sign the requests and the backend validates the signature, allowing or denying actions depending on predefined policy. The predefined rules are known as [IAM](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies.html) policies and automatically configured by the Amplify CLI.
 
-The first mode is a common authorization method for REST or GraphQL APIs, while the second mode is necessary for interfacing with AWS services such as S3, Pinpoint, Sumerian, and others. 
+The first mode is a common authorization method for REST or GraphQL APIs, while the second mode is necessary for interfacing with AWS services such as S3, Pinpoint, and others. 
 
 ## Sign-up and sign-in
 

src/fragments/lib/xr/getting-started.mdx

@@ -1,6 +1,8 @@
 <Callout warning>
 
-Your Sumerian scenes will no longer be available as of 2/21/2023. Consequently, the XR category will be unavailable. You can use Babylon.js, an open source 3D engine to author scenes in the future. Please see [Babylon.js sample](https://github.com/aws-samples/aws-tools-for-babylonjs-editor) for examples on using Babylon.js and publishing your scenes with Amplify Hosting.
+The Amazon Sumerian service is no longer accepting new customers. Existing customer scenes will not be available after February 21, 2023. The AWS Amplify XR features depend on the Amazon Sumerian service to function and as a result, will no longer be available.
+
+For more information, please see: https://aws.amazon.com/sumerian/
 
 </Callout>
 

src/fragments/lib/xr/sceneapi.mdx

@@ -1,7 +1,8 @@
 <Callout warning>
 
-Your Sumerian scenes will no longer be available as of 2/21/2023. Consequently, the XR category will be unavailable. You can use Babylon.js, an open source 3D engine to author scenes in the future. Please see [Babylon.js sample](https://github.com/aws-samples/aws-tools-for-babylonjs-editor) for examples on using Babylon.js and publishing your scenes with Amplify Hosting.
+The Amazon Sumerian service is no longer accepting new customers. Existing customer scenes will not be available after February 21, 2023. The AWS Amplify XR features depend on the Amazon Sumerian service to function and as a result, will no longer be available.
 
+For more information, please see: https://aws.amazon.com/sumerian/
 </Callout>
 
 ## Using optional progress handlers and options