There is a formal group, the Steering Group, which represents the browsers that implement WHATWG standards, and serves as the point of final appeal if the community doesn't come to a consensus on its own. But this is similar to the W3C appeals track where if all the paying member companies don't come to consensus, they appeal to "The Director" as the ultimate decider. ("The Director" is nominally Tim Berners-Lee, but recently all Director decisions have been made by W3C management "on behalf of" The Director.)