The EC2 discovery plugin uses the AWS API for unicast discovery.
If you are looking for a hosted solution of Elasticsearch on AWS, please visit http://www.elastic.co/cloud.
Version 7.0.0-alpha1 of the Elastic Stack has not yet been released.
The plugin can be removed with the following command:
sudo bin/elasticsearch-plugin remove discovery-ec2
The node must be stopped before removing the plugin.