Yeah, that's totally true. I guess there the complexity mostly comes more from the preexisting complexity of people.
edit: also realised recently that TTRPGs and other storygames are even more extreme examples of this.
I guess it feels different though, because IMO Go leads to an understanding of emergent complexity precisely because the rules and mechanics complexity is tiny. TTRPGs rely on the already extreme complexity of humans to produce their complexity, so you're going from very complex to very complex, which is less surprising.
Also, I'm wondering if this has something to do with Chris Langton's work... e.g.Computation at the edge of chaos: Phase transitions and emergent computation