I don't get why some people here are saying that you used to be free to say anything online without risk. I'm guessing either the rose-tinted glasses are on or memories are fading. Either way, it was never that way either online or offline.
Small forums had mods who policed hard and made rules their clique followers obeyed and enforced. Getting banned was a common occurrence for the slightest out of line comment. Bigger forums had a TOS you were expected to read through and follow, and they were stricter than the rules we have these days. Swearing could get you banned from GameFAQs, for instance. The only "anything goes" forums were the ones run by the guys everyone else was trying to keep out because they were filled with seriously messed up people. (Keep in mind, we had a domestic terrorism problem in the 90s, and people were afraid of those guys joining forums, as they were known to have their own and to try infiltrating others.)
Today, we have social media corporations that are completely amoral, not concerned about little things like swearing, and not concerned about the big problems either. Some of the stuff people post on Facebook, Reddit, Twitter, Pixiv, and other big sites would have got them permabanned from 95% of all forums back in the day.
Yes, you can get "cancelled" now, but cancelling actually does less now than ever before. Celebrities who got cancelled often make more money and get more opportunities after being cancelled. (Notice Mr Beast got a TV show, and the Paul brothers are swimming in post-dead body desecration money.) This is a far cry from the 90s, when Dave Sim's career went from "darling author of Cerebus the Aardvark" to "lunatic who will never succeed in the field again" after he went on his notorious rants. Granted, people got away with a lot back then too, but when the public was aware of it, they got truly cancelled; they only got away with the things not widely printed in the media or ignored by TV.
Fact of the matter is, social media doesn't care what you say as long as you make them money. When money wasn't a part of it, people insisted on having decent communities, for better or for worse. And there's a mix of that now: we're better in that it's easier to avoid being censored over basic social faux pas, but we're worse in that every idiot is allowed to cry "freeze peach" to get away with everything from harmful behavior to illegal behavior.
The forums are virtual projections of uninhabited islands devoid of any form of life, which Instead of floating on real water, they are suspended above this vast synthetic ocean called the internet.
Therefore, being places without a soul, it is only the state in which they were created; their administrative management and the people who frequent them through their avatars, which give the forums a certain type of environment and personality.
These variables are highly diverse and make each place very unique and not perfectly identical to any other.
Given what has just been said, it is easy to acknowledge that even in the past, there were forums that were very strict and intransigent, like the ones you mentioned.
However, that does not reflect a unique reality of how things were back then, because during the same time period, there were also gathering places where almost no rules whatsoever applied.
This led to words and actions that today would not even be conceivable on certain image boards named with numbers and suffixes, which seem almost honorific.
Let me give you some practical examples.
When I was in high school, there was this 'classmate' of mine who looking back probably exhibited psychopathic traits, because he had an obsessive fascination with looking at photos and videos of people who had been victims of car accidents.
At the time, these were easily visible in the first row of Google Images (there was no blur filter), while today on WhatsApp, I'm not even able send a video of myself eating a chocolate during the summer, because since it was slightly melted, the algorithm apparently has thought that it was that other similar thing, which usually comes from an intermediate area, which is located between the back and the legs...