Let me see if I understand the situation fully. The 7.0.0 release of Elastic has deprecated the old TransportClient class, and the NodeClient class was deprecated all the way back in 2016. No alternative is present in any of the packaged .jar files.
The new preferred Client class is RestHighLevelClient, but it's not included in the .jar files packaged with the 7.3.0 download - three versions after it was introduced. The only place where you can actually get it is from github, where it is provided as loose source along with hundreds of other files, all in different directories that all nest a dozen deep.
So someone who downloads the 7.3.0 release of Elastic and attempts to load the .jar files that are provided as an API will discover that there is literally no supported way to connect to the Elastic service. Did somebody compile the wrong build or something? Why would I need to rebuild the libraries myself with Maven to use this?