I think it will still have great difficulty understanding and manipulating causal relations when they’re framed in a manner different from the training data. E.g., you describe two different sets of causal relations: A->B, A->C and A->B->C, then ask about how intervening on B influences C. In the A->B->C case, C is affected by the intervention, but in the A->B, A->C case, C is unaffected. GPT-3 predicts an effect in both cases. See pages 8⁄9 of Using cognitive psychology to understand GPT-3.
I think it will still have great difficulty understanding and manipulating causal relations when they’re framed in a manner different from the training data. E.g., you describe two different sets of causal relations: A->B, A->C and A->B->C, then ask about how intervening on B influences C. In the A->B->C case, C is affected by the intervention, but in the A->B, A->C case, C is unaffected. GPT-3 predicts an effect in both cases. See pages 8⁄9 of Using cognitive psychology to understand GPT-3.