A later patch even made it so disabling pacts doesn't even turn off achievements anymore.
2.6, released with The Reaper's Due, reverted calls-to-arms to an improved version of the old voluntary system (you can now betray the alliance again, but with stiff penalties) and added a game settings panel with the option to disable defensive pacts, as well as adding practical reasons to stay in peacetime for longer periods and wait out defensive pacts. Author's Saving Throw: Conclave was controversial at best, though less for what was in the DLC and more for what was in the 2.5 rules patch: namely defensive pacts against expanding empires and mandatory calls-to-arms from allies, and to a lesser extent not being automatically allied with foreign rulers of the same dynasty.This implies that the upcoming decimation of the Aztec Empire in the Age of Discovery was a Roaring Rampage of Revenge.