The current docs

https://docs.redhat.com/en/documentation/openshift_container_platform/4.21/html-single/virtualization/index#virt-updating-virtio-drivers-windows_virt-installing-qemu-guest-agent

only mention the windows update service to update the drivers. This is not convenient for many system admins so instead they will either use the ISO duirectly or mount the new drivers disk again. 

In RHEL docs we have 
https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/9/html/configuring_and_managing_virtualization/installing-and-managing-windows-virtual-machines-on-rhel_configuring-and-managing-virtualization#proc_updating-kvm-drivers-on-a-windows-guest_installing-kvm-paravirtualized-drivers-for-rhel-virtual-machines 
and the additional important hint that updating the drivers by reinstalling will impact network config. 

This should be documented in OCP-V as well.