IDK but whatever it was he hung around for the second season unannounced until the character returned halfway through.
>but its not the main focus and is forgotten in later seasons
Not true. In the second season it's a mess that goes nowhere, but they do frame the human vs robots conflict in an obvious parallel to class. The third season weirdly is about literal capitalism and conflict between humans and AI-embodied capital (or more accurately AI-embodied humanity vs AI-embodied capital), but since capitalism has evolved into AI-monarchy there's no direct criticism of the present capitalist system and it's more about AI or the alienated logic of capital driving civilization. But that's giving it a lot of credit for a show that by this point has a couple good ideas and doesn't even know how to execute those properly.