People use the word "censor" to mean so many things that it's hard to track, but in this case was HN working the way it always does and has for many years. It works the same way regardless of topic, and there was no moderator intervention. We sometimes intervene to turn off flags, but this wasn't the right thread for that, as I explained here: https://news.ycombinator.com/item?id=38657527.
The topic itself just had two massive threads on HN (https://news.ycombinator.com/item?id=38616550 and https://news.ycombinator.com/item?id=38572675), so I don't think it's correct to call the topic censored.
Re transparency, we don't publish a complete moderation log (I've written about why over the years: https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...), but we're happy to answer questions when people ask them, and believe it's in HN's long-term interest to err on the side of openness. I spend half my days these days answering this sort of question through email. Even when we can't answer a question completely, we can usually at least say why (e.g.: some of HN's anti-abuse software would stop working if we published how it works, so we can't answer that question completely).
If you or anyone still has a question that I haven't answered here or https://news.ycombinator.com/item?id=38657527, I'd be happy to take a crack at it.
I think that marking the actual post as "flagged" or "censored" would make it clear what is happening. A big banner across the top so that everyone on the post knows that their comments don't matter and they have been essentially cut off from the rest of the community.
Hacker news however prefers doing things on the sly and that makes people feel bad. It is the opposite of open and transparent.