ElasticSearch is not to be used as your primary data store. It's a search tool and you should have a process to rebuild an index from your primary data store.
Outside of that, I highly recommend using a managed service, either AWS ElasticSearch service, or Elastic.co to make recovery and management easy. AWS does a snapshot on every index every couple hours and it's relatively simple to restore a deleted index.
Also, I'm sure the author knows this now, but don't ever run any command on a live production data store without triple checking it.
Outside of that, I highly recommend using a managed service, either AWS ElasticSearch service, or Elastic.co to make recovery and management easy. AWS does a snapshot on every index every couple hours and it's relatively simple to restore a deleted index.
Also, I'm sure the author knows this now, but don't ever run any command on a live production data store without triple checking it.