Actually, I think you may have a point. Not that we can be sure, but if I went by the name, it would be most plausible to assume all clans are represented.
I can still see the other possibility being plausible, but yes.
In any case, we'll see. If it is major clans, there's likely relatively few people there. Maybe like the Godsmoot or a little more. If it is all clans, it would likely be more like a large parliament.