I have never seen any fandom actually be able to coordinate decision-making about what is and is not part of that fandom, and I've been in the RPG industry in one way or another since the late 80s.

We won't even talk about the sci-fi/fantasy/speculative fiction/SF/high magic/low magic/steampunk/dieselpunk/you-name-it fandom communities, who all seem to spend about as much time trying to decide who to define out of the community as looking for things to be in it.

Not that I'm cynical. Never that.