Are you a delusional oldfag or very new and naive ?
There haven't been ANY board that doesn't moderate specific topics.
Text only boards like 2ch are not exempt,and also delete political posts for exemple.
Jannies always curate context and content,and only those who see the posts disappear can tell you if they are censored,and you can't check whether or not they're lying to you (since it's anonymous)
Even off-topic posts also get deleted all the time to curate threads.
Your exemple is one of the worst to choose too as others have already mentioned,any thread made on here would get deleted on /pol/ in less than a day.