I understand what you mean, but I'm not entirely sure it is the case. If you will allow me, I would like to elaborate on it.
The Aetherlight may have been what caused Evercuty to spin. This power could have also gone out from Evercity to keep other Great Engines running. This would mean that the Fog would be kept back for good and we would no longer need to fill the Great engines from our Aethermeters.