Update mdo-support-teams-about.md

Author: chrisda

defender-office-365/mdo-support-teams-about.md

@@ -35,6 +35,8 @@ All licenses of Microsoft Teams in Microsoft 365 include the following built-in
 - [Built-in virus protection in SharePoint, SharePoint Embedded, OneDrive, and Microsoft Teams](anti-malware-protection-for-spo-odfb-teams-about.md)
 - **Near real-time URL protection in Teams messages**: Known, malicious URLs in Teams messages are delivered with a warning. Messages found to contain malicious URLs up to 48 hours after delivery also receive a warning. The warning is added to messages in internal and external chats and teams for all URL verdicts (not just malware or high confidence phishing).
 
+  Currently, this feature is on by default, and there's no way to disable it.
+
   :::image type="content" source="media/teams-message-url-warning.png" alt-text="Screenshot showing a Microsoft Teams message with a URL warning." lightbox="media/teams-message-url-warning.png":::
 
 Microsoft Defender for Office 365 provides the following extra Teams protection features: