Dead Wyrms send non-wyrms to council meetings. We appreciate the ... appetizers, but I think they get eaten before they say much.
Seriously : I think that only living Wyrms should be able to speak in council. I'm willing to extend some leeway to the one dragon, mainly because he didn't design his own pretender, plus live dragons are hugely different from dead wyrms sending tiny minions.
It is, after all, a council of Wyrms. Not a council of the fleas hiding between the scales of dead Wyrms, such vermin not to be confused with .... Vyrmin.