When prevent dom0 telling Qubes-Whonix VMs the time T397 is implemented, whonixcheck should add a sanity test to see if that won't break over time.
Implementation:
- qubes-whonix 12's /etc/qubes-rpc/qubes.SetDateTime[.anondist] can forward everything dom0 is [not] telling to a file.
- From there whonixcheck can check if that file exists. If it exists, then T397 is either broken or not yet implemented.