How can "AI" facilitate genocide? Like what might chatgpt have suggested that would have made the nazis more effective or the khmer rouge.

Widespread mass realtime facial recognition usage is allowing governments to target and repress subsets of the population with an unprecedented scale and efficiency. ICE are flying facial recognition drones over sidewalks in downtown LA. Dissdents are having their facial geometries entered into secret databases simply based on political opinions.

Any new technology throughout history has first been used for war and genocide.

How could modern AI have helped those groups you mention in their endeavour? Really fucking easy and effectively, and you don't need a lot of imagination to think of how. From surveillance and interrogation to pinpoint determination of ethnicity and much more. Not to mention translation between human languages.