Free speech doesn't mean you get to say whatever you want to with no consequences. Private entities, in particular, but also the government, have the right to limit speech in certain contexts. For private entities, this pretty much means in whatever way they want to, as long as it isn't an illegal reason such as discrimination against a member of a marginalized or protected class. There is absolutely no inherent free speech right to be abusive and in the past Medium has done a better job than most platforms in curtailing that. Looks like those days are now over...