DAG does seem natural here. Having a LLM add metadata to the nodes can make this even cooler. For instance, person A presents statement Sa. Person B comments on person A's statement, Sba and person C comments on person A's statement, Sca. The viewers now, especially new parties that are joining the conversation, would be able to see that Sba agrees to most of Sa said, but refutes a fact said by Sa. Sca doesn't agree with anything Sa is saying. Another example would be, nodes getting more weight as more people agree with it and smaller as more people disagree. Obviously, the implementation and implications are boundless.