That's the most common pattern indeed. Note they tried to find a vision by themselves without an "official" leader. They were unfortunatly unable to find one apparently.
However, I believe a kind of implicit vision has emerged which is simply to make sustainable such a place. Put another way, people who are attracked by this implicit vision (such as the author of the article) are still with them, and the others have probably left because this was not a vision they were inspired by.
One can outsource leadership in a variety of ways. A highly cohesive and capable group can do consulting projects and self-organize around the project, for example.
However, I believe a kind of implicit vision has emerged which is simply to make sustainable such a place. Put another way, people who are attracked by this implicit vision (such as the author of the article) are still with them, and the others have probably left because this was not a vision they were inspired by.