I think what people are forgetting here is that there's a big difference between censorship (by a government, for example, which is constitutionally prohibited in the US) and having rules in a private forum, or in a game. There's already been a few court cases that have ruled private forums and venues have the absolute right to decide what is or is not appropriate language or behavior within the boundaries of the private venue. If the creators of a private venue decide they want to create such a place where profanity is not permitted, it is their absolute right to do so. You can of course disagree with them for doing so, but they are not obligated to change what they are doing because of it.
I'm sure there's more than a few types of behaviors most people would prefer not to have in their homes or businesses or places of worship. Nobody questions that right. But as soon as it's an internet venue for some reason that right inexplicably gets called into question.