It's technically pirating because the license of Windows for ARM does not allow end users to run it on arbitrary hardware or virtualize it. I have doubts that they'd ever actually enforce those terms though.
Microsoft does not agree:
>Yes customers can use retail copies to run Windows 10/11 on Macs, including ARM Macs. The Windows retail EULA does not have any use rights restrictions on the type of device you install Windows on.
https://getwired.com/2022/02/03/can-you-run-windows-on-arm-o...