I hope their strategy for saying this is to scare off the clickbait mongers and not to try to turn the focus of this platform to becoming a marketplace for "coaches" to sell their consultancy services. Because IF Medium ever becomes just "a repository for your articles and gives you the opportunity to store articles for free," then it becomes just another social media platform.
The reality is that if Medium wants quality content from quality writers, they have to pay for it. I think they understand that, that one statement notwithstanding. Medium is a platform for quality writers to make money, that's why it is a quality platform for readers who pay for it.