It already does run on ARM64 but it is only available to OEMs, meaning that you can't buy it as a consumer. And it only runs on some specific SoCs, most of which are Qualcomm ARM chips.
Things are likely to change as more actual ARM64 laptops appear. Some Windows on ARM64 laptops are already available like the HP Envy X2, the Lenovo Yoga C630, and the Microsoft Surface Pro X.
Things are likely to change as more actual ARM64 laptops appear. Some Windows on ARM64 laptops are already available like the HP Envy X2, the Lenovo Yoga C630, and the Microsoft Surface Pro X.