Source of WNS Notification in Intune Expedite Update Policy

Hello,

When creating an expedite update policy via Microsoft Intune, a WNS (Windows Push Notification Service) notification is sent to the device to trigger the MDM session and apply the policy.

Once the policy is applied, the device installs the update immediately using the Microsoft Update Health Tools.

My question is:

Is the WNS notification sent by Intune to trigger the MDM session also responsible for initiating the expedite update installation?

Or:

Does the Windows Update for Business Deployment Service (WUfB-DS) send a separate WNS notification to trigger the scan and installation via the Update Health Tools?

I’m looking for an official clarification on whether WUfB-DS plays an active role in sending WNS notifications in this scenario, or if the initial Intune-triggered WNS notification is sufficient to initiate the expedite update.

Thank you in advance for your insights!