Actually, the argument you just advanced is precisely the reason why we thought making it more inclusive was the appropriate way to go. It's true that one can't always contemplate, for all time, what might evolve into an additional form of civil society. It seems to me that the point is to make it as inclusive as possible, as you've suggested. At some future date, then, one could make a change if somehow it wasn't inclusive enough.
But when I listen to your argument, it seems to support the amendment that I've put forward.