Learn Editor: Update whats-new-in-microsoft-defender-endpoint.md

Author: pahuijbr

defender-endpoint/whats-new-in-microsoft-defender-endpoint.md

@@ -46,6 +46,10 @@ For more information on what's new with other Microsoft Defender security produc
 - [What's new in Microsoft Defender for Cloud Apps](/cloud-app-security/release-notes)
 - [What's new in Microsoft Defender Vulnerability Management](/defender-vulnerability-management/whats-new-in-microsoft-defender-vulnerability-management)
 
+## July 2025
+
+- (Preview) Added support for Azure Stack HCI OS, version 23H2 and later. This support will roll out gradually across all clouds and regions in July.
+
 ## April 2025
 
 - (Preview) **Contain IP addresses of undiscovered devices**: Containing IP addresses associated with devices that are undiscovered or are not onboarded to Defender for Endpoint is now in preview. Containing an IP address prevents attackers from spreading attacks to other non-compromised devices. See [Contain IP addresses of undiscovered devices](respond-machine-alerts.md#contain-ip-addresses-of-undiscovered-devices) for more information.