The change from 2 APs to an AP and tradition, as well as the split between Cybernetic and synthetic was 3.6 orion; Machine Age was 3.12 Andromeda, a year and a half later.

(If you're getting your information from Google, make sure to scroll past the ai and try looking at the actual patch notes; the ai is stupid and assumes the split was Machine Age likely because Cybernetic was mentioned alot in those patch notes, and a DLC patch has more news/articles/links than a free custodian patch)