It’s pretty easy. You just check if the project is led by a community of people, join the conversation room for a while and feel the vibe in there.
A bad indicator is always if a project is mainly led by a single person, more so if it’s not covered by an umbrella project that looks over it. And even more so if the projects upstream dislike them.
Nobody can speak for the movement at all. We all are part of it, but everyone is able to decide who you trust, who you work with and what you do in general with your time in that space.