I don't think White Council will be taken down, it will go through some changes to some other form most probably, but even if it's disbanded there will be wizards who'd come together to build some form of governance or at least alliances, which eventually be another version of White Council.
Besides, Rashid seems like a reaaally hard guy to kill and he supports White Council; there's also unavoidable needs for centralized power nexus to combat truely evil wielders of black magics, like necromancers.