I can't see why there would be a need to prevent nodes creating additional addresses. In any event, there's no way you could ever control that from the blockchain since it's just a local action that takes place on the node, and any user can install a modified version of MultiChain to work around an official restriction. The point of permissioning on the blockchain is to only allow certain addresses to connect, send, receive, etc... – that is the direction I believe you should be looking in to restrict address usage.