Hard-coded shutdown that follows a completed ascendency, putting the system to sleep for elemental reclamation.
Fopsy explains the rule to Baroness Victory and Carl: once the Ascendency is considered finished, assuming there are no crawlers left, it automatically triggers the system's shutdown and hibernation sequence. This is a hard-coded limitation, not a policy choice, and it exists to allow Elemental Reclamation before the system is woken back up.
Because it cannot be overridden, it has become a weapon. Fopsy reasons that with The AI spreading rapidly, forcing an early ascendency ending is a possible alternative to the failsafe — a way for the Residuals agent behind War Mage Rebellion to shut everything down and protect The Eulogist.
The unstoppable consequence the war mages are trying to trigger by killing every crawler.