This is the equivalent of retiring the domain name itself. If you stop renewing it anyone can hijack it and serve whatever they like. Not to forget, they will a

This is the equivalent of retiring the domain name itself. If you stop renewing it anyone can hijack it and serve whatever they like. Not to forget, they will also get email intended for that domain. Anyone sane will keep the domain name and ns infrastructure and serve a 301 HTTP redirect. All anyone is proposing here is to override the TTL to something longer (like 48h) if the nameserver is unreachable. Of course the perfect solution would be to have the recursive nameserver fetch the correct record from a blockchain.