Poor Datastax. Another company killed by AWS.
They can probably support their product line atop this just fine. They really make their money on integrating cassandra and a bunch of other big data frameworks in one neat little package.
I don't know of any company "killed" by AWS, and I don't think that Datastax will be either.
I know at least three founders who had to shut down after AWS launched a feature at re:invent.
One went on to start another company that was acquired by Facebook in an 8 figure deal.