The gate network didn't collapse, the sector was purposely isolated.
- Not a lot to back this up due to the paucity of information with regards to the collapse, but between the Omega and the freaky sensor ghosts that don't seem to have much explanation it seems not unreasonable to assume that the domain chose to isolate the Sector as a sort of quarantine measure. Alternately, the Domain came under attack from something, possibly the aforementioned Omega and chose to isolate the Sector to keep humanity alive.
Omega was the most advanced AI developed by the Domain before the ban.
- The Coronal Hypershunts were considered a critical piece to powering the Domain and it's industries. So it wouldn't be far fetched that the Domain government would want it to be very well protected, and so used their greatest technologies to develop Omega and it's ships, which would do the job of guarding it from anyone trying to sabotage it. Then something eventually went wrong, leading to the ban on AI.
- On the other hand, it's possible that the Domain government didn't want anyone else to develop a similar AI to their own, and so put out bans and restrictions to maintain a monopoly.
Alpha Cores are designed to think like humans and surpass their capabilities. Omega does the opposite, thinking in the most inhuman terms possible
- Alpha Cores have superhuman intelligence but still think like humans. Like the Gamma and Beta Cores they are built on the principle of functioning the same way humans do. Omega is designed to do the opposite; it's on par with an Alpha Core or higher, but is designed not to think like a human. Omega explores the other possibilities to try to come up with ideas or technologies humans and Alpha Cores would have missed. Unfortunately it worked too well and being inhuman, its betrayal was too alien to understand until the gate network collapsed.
