Add deprecationDate to whats-new and fix changelog CreatedDateTime (#28621)

Agent-Logs-Url: https://github.com/microsoftgraph/microsoft-graph-docs/sessions/c9dc1142-6b95-444c-b409-0833ecee4a21

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Co-authored-by: FaithOmbongi <14026935+FaithOmbongi@users.noreply.github.com>

Author: Copilot

changelog/Microsoft.AppManagement.json

@@ -14,7 +14,7 @@
       "Id": "698db058-5109-4754-80a9-b05647cd3d80",
       "Cloud": "Prod",
       "Version": "beta",
-      "CreatedDateTime": "2026-03-25T10:12:42.1289461Z",
+      "CreatedDateTime": "2026-04-09T10:12:42.1289461Z",
       "WorkloadArea": "Applications",
       "SubArea": "Service principal"
     },

concepts/whats-new-overview.md

@@ -39,6 +39,10 @@ Removed the `model` parameters and payment-model guidance from Microsoft Teams e
 
 ## April 2026: New in preview only
 
+### Applications
+
+Added the **deprecationDate** property to the [applicationTemplate](/graph/api/resources/applicationtemplate?view=graph-rest-beta&preserve-view=true) resource to indicate when an application will be removed from the Microsoft Entra application gallery.
+
 ### Backup storage
 
 - When a [protection policy is deactivated](/graph/api/protectionpolicybase-deactivate?view=graph-rest-beta&preserve-view=true), backup activity stops immediately, no new backups are taken, and the protected resources are no longer covered by the policy. Any backups taken before deactivation are retained according to the retention policy, after which they're offboarded. You can restore data using previous restore points even after deactivation.