Windows 11 24H2 - Copilot Removal

As stated in Microsoft documentation, the OMA-URI policy will be depreciated and will not work on 24H2. 

You need to use an AppLocker policy to block the app pre-24H2 deployment or use Powershell script to uninstall the application. These solutions can be found here - https://learn.microsoft.com/en-us/windows/client-management/manage-windows-copilot#remove-or-prevent-installation-of-the-copilot-app

From experience, using the AppLocker policy after the 24H2 update is pushed may show your users a pop-up window claiming that "Administrator has blocked this app." If you have already deployed 24H2, you might need to use both the AppLocker policy to block the app and the PowerShell script to uninstall the application.

https://learn.microsoft.com/en-us/windows/client-management/mdm/policy-csp-windowsai#turnoffwindowscopilot