I genuinely don't understand what you're trying to say. Most of the records were destroyed and we're trying to piece together the evidence. What is the "truth" that we are "not allowed" to bring up?
I think the other HN thread I linked on this subject shows that you are not correct that discussion of conspiracy theories is completely taboo here. As someone quite steeped in the conspiracy world, some of the most intelligent analysis and thoughtful pushback to the "there's no such thing as conspiracies" bluepill perspective has been on HN, and in general it has not been suppressed or downvoted unless advanced in very combative terms.
Although perhaps you're right that if you start bringing up Project Monarch or the like you might get some pretty severe pushback. Even then I'm not sure you'd necessarily be downvoted to oblivion.