I think there is a difference between corporate social media and the fediverse that you should keep in mind here. The former dont care about racism etc because hostility actually generates more "engagement" and advertising money, plus the site owners will never actually see it. But on the fediverse its very different, because instances are run by volunteers in their free time, who want to have a site that they enjoy using. So being civil will go a lot further here (it definitely does on lemmy.ml). For that reason, your warning still stands.