The author does a disservice to their audience:
> As has happened before, Amazon took the open-source side of Elasticsearch, did a hard fork, and has been selling it as a hosted service, slowly implementing their own versions of features that have been available in one form or fashion in mainline Elasticsearch for years.
When what happened was Elasticsearch changed its licensing model after benefiting off of the open source community for years to be more restrictive, forcing the fork.
1 - Amazon blog post announcing fork https://aws.amazon.com/blogs/opensource/keeping-open-source-...