Quick answer from the wiki
7.029
The "when a core guard post dies, launch a revenge exo" logic has been replaced by logic where:
When a core guard post on an AI HW drops below 75% health (or dies), that HW schedules an exo 10 minutes from then.
When that exo launches, another larger exo is scheduled 30 minutes out. Then another still-larger 30-minute one after that, etc.
If the AI home command station on that planet dies, any of its scheduled assault-provoked exos are cancelled (even if the other AI home command station is still alive).
Just like the logic this is replacing, it doesn't happen at all if the "Lazy AI" lobby modifier is on.
Grav Reactor core posts don't trigger this, since they sometimes have to be killed much earlier in the game.
Thanks to Faulty Logic and others for inspiring this change.