It's may well be too late for posting these to be meaningful, but:
What was the task outside the galaxy that was occupying the AIs' attentions in AIW? (unless this is answered somewhere in AIW I haven't found)
Have you played the Fallen Spire 'minor' faction? It contains the answer to your question.
Ah, my bad. I started but never finished Fallen Spire.
I have to point out that Chris has been asked the question several times and never deigned to answer or even dodged the question entirely.
On that same note I'm curious about the Spire minor factions. They seem like something worth building an entire AI War expansion around, but maybe the Spire in SBR could tell us about their darker cousins before then.