I feel for AWS here
However childish AWS's responses was, I do feel for them in this case (and it's a lot less childish than the continuous digs at AWS in Elastic's blog posts), partly because the article they were complaining about looked like it came straight out of elastic's marketing department, it wasn't journalism in any form.
Elastic have been a particular poor open source citizen in this case. Firstly, having attracted contributions from many (including me) into the open source elasticsearch code, Shay has now gone back on his statement that elasticsearch would never be 'open core'. It's now a commercial product, the fact that a small amount of code is still open source doesn't make it an open source product. Secondly, they've merged open and closed source into the same repo which shows the direction they're headed in, and the extent to which they (don't) value their community.
When Shay chose the Apache licence for elasticsearch, he did so because he wanted people to use it commercially (otherwise he would have chosen a different licence...) because he needed the contributions that those companies (including AWS) would make to his code. He's now making quite a lot of money out of some code which has been contributed to by those same commercial organisations. In addition, elasticsearch is heavily dependent on Apache Lucene - in the latter years the main contributor to lucene was employed by IBM (to work on lucene full time iirc). So the money that Shay is making from elasticsearch now is partially driven by code that IBM spent money creating. It certainly feels like a contradiction to say it's ok for elastic to use code paid for by other companies, but then for some reason AWS isn't allowed to use elastic's code.
I'm pretty sure that the majority of elastic's complaint is simply that AWS are competing against elastic's own search-as-a-service, but they're trying to use allegations of poor open source practice to cover that up.
If Elastic don't want people to use their code commercially, they should use a licence that forbids it. This childish anti-competitiveness is helping no one except the lawyers.