Currently, it’s perfectly acceptable for a Vassal not to send an Assign Virtual Action and just let their Serfs remain in the currently-assigned tasks. However, due to the rules regarding progressing to the next Fortnight, this causes the maximum wait time of 72 hours. Adding a “no-op” Virtual Action allows Fortnights to occur sooner if a Vassal wishes to leave things as-is.

The counter-argument is that it’s just as much trouble to send “No Change” as it is to just repeat the prior Assign Virtual Action. This is true at the moment, but if we start adding more Virtual Actions, it will become simpler to issue a “No Change” if that is what is desired.