It would be interesting to know how they will judge the results of this experiment when it concludes.
I respectfully disagree that discussion of politics on HN cannot "meaningfully change or move forward the debate and is unlikely to be instructive". Indeed, I have witnessed proof that this is not so. I have seen numerous occurrences in comment threads where there has been spirited factual debate which ended up informing both sides. I have seen minds changed. I have experienced my own mind being changed.
I don't deny, of course, that there has been some...less useful discussion, as well. But I feel that overall, it has been positive.
I say this as someone whose been that spectator.
I feel like healthy political discussion would be a meaningful change. If thoughtful people all abstain from the topic, it will surely get worse. The immediate goal isn't to "win" arguments. It's not to be confused about why someone would disagree. Or even agree! Maybe they do but there's no place to say that.
Personally, I don't plan to discuss politics any more or less than when this topic was posted, so I guess I'm not part of the experiment.