They talk about the importance of governance, but not how it will be like. What science, theories and principles will guide the governance structure? In politics, we have a system developed in the 18th century, for the reality and technologies of that time. Nowadays we can create much better systems, with liquid democracy and similar things. One thing that I think is important is that the governance system can be changed relatively easily, but also in a controlled and democratic way. Another idea is to create different governance systems, and see which ones work best.
There is no clearity who will finance such large social media plateform. If they really interested for decentralized plateform then it should be funded by a single person.