If they started removing low-emotion information and discussions that just didn't fit the Bogleheads philosophy, I think that would cross the line into censorship.
Anyway, it's clear that the Bogleheads forum model is the polar opposite of where Facebook, Twitter, and Reddit have gone to suck in the masses and increase their engagement by highlighting the most heated stuff and throwing gasoline onto the fire with likes, votes, and retweets. I think the mainstream social media companies have put themselves into a bind with this.
Maybe moderation is part of that, but I’d argue the subject matter is already generally less polarizing/toxic than what’s on the other three platforms.
But your point is still valid re: how Bogleheads does moderation.
What's obviously very hard is allowing discussion of politics, macroeconomics, religion, race, etc. without it getting heated. Bogleheads doesn't even try.