[Outlook](legacy tokens) Updates now that legacy tokens are off (#5451)

* Updates now that legacy tokens are off

* fix toc for article updates

* fix links add redirect

* link and title fix

* Apply suggestions from code review

Co-authored-by: Sam Ramon <15154970+samantharamon@users.noreply.github.com>

---------

Co-authored-by: Sam Ramon <15154970+samantharamon@users.noreply.github.com>

Author: davidchesnut

.openpublishing.redirection.json

@@ -1365,6 +1365,10 @@
         {
             "source_path": "docs/outlook/compose-scenario.md",
             "redirect_url": "/office/dev/add-ins/outlook/outlook-add-ins-overview"
+        },
+       {
+            "source_path": "docs/outlook/turn-exchange-tokens-on-off.md",
+            "redirect_url": "/office/dev/add-ins/develop/faq-legacy-exchange-tokens"
         }
     ]
 }

docs/includes/legacy-exchange-token-deprecation.md

@@ -1,2 +1,2 @@
 > [!IMPORTANT]
-> Legacy Exchange tokens are deprecated. Legacy Exchange [user identity](../outlook/authentication.md#exchange-user-identity-token) and [callback](../outlook/authentication.md#callback-tokens) tokens have been turned off for most Exchange Online tenants. Administrators can reenable legacy tokens for tenants and add-ins until June 2025. In October 2025, legacy tokens will be completely turned off for all tenants. For the timeline and details, see our [FAQ page](../outlook/faq-nested-app-auth-outlook-legacy-tokens.md). This is part of [Microsoft's Secure Future Initiative](https://blogs.microsoft.com/on-the-issues/2023/11/02/secure-future-initiative-sfi-cybersecurity-cyberattacks/), which gives organizations the tools needed to respond to the current threat landscape. Exchange user identity tokens will still work for Exchange on-premises. Nested app authentication is the recommended approach for tokens going forward.
+> Legacy Exchange Online [user identity tokens](../outlook/authentication.md#exchange-user-identity-token) and [callback tokens](../outlook/authentication.md#callback-tokens) are no longer supported and turned off across all Microsoft 365 tenants. If an Outlook add-in requires delegated user access or user identity, we recommend using [MSAL (Microsoft Authentication Library) and nested app authentication](../develop/enable-nested-app-authentication-in-your-add-in.md). Exchange user identity tokens are still supported for Exchange on-premises.