Update defender-for-office-365-whats-new.md

Added sections for December 2024 ("Considerations for integrating non-Microsoft security services with Microsoft 365") and November 2024 ("Microsoft Ignite: Redefining email security with LLMs to tackle a new era of social engineering" blog post). 

Tagging @chrisda for awareness.

Author: PaulRNewell

defender-office-365/defender-for-office-365-whats-new.md

@@ -39,6 +39,14 @@ For more information on what's new with other Microsoft Defender security produc
 - [What's new in Microsoft Defender for Identity](/defender-for-identity/whats-new)
 - [What's new in Microsoft Defender for Cloud Apps](/cloud-app-security/release-notes)
 
+## December 2024
+
+ - [Considerations for integrating non-Microsoft security services with Microsoft 365](mdo-integrate-security-service.md): considerations and recommendations for deploying a defense-in-depth email security strategy using third-party security services. 
+
+## November 2024
+
+ - **Introducing LLM-based BEC detection and classification**: Microsoft Defender for Office 365 now detects BEC attacks using large language model (LLM)-based filters to analyze an email's language and infer intent. To learn more, see our blog post [Microsoft Ignite: Redefining email security with LLMs to tackle a new era of social engineering](https://techcommunity.microsoft.com/blog/microsoftdefenderforoffice365blog/microsoft-ignite-redefining-email-security-with-llms-to-tackle-a-new-era-of-soci/4302421). 
+
 ## October 2024
 
 - **Tenant Allow/Block List in Microsoft 365 now supports IPv6 address**: The [Tenant Allow/Block List](tenant-allow-block-list-about.md) now supports [allowing and blocking IPv6 addresses] (tenant-allow-block-list-ip-addresses-configure.md). It's available in Microsoft 365 Worldwide, GCC, GCC High, DoD, and Office 365 operated by 21Vianet environments.