I don't see this at all. The "extinguish" phase is usually done when a product is acquired by a direct competitor to acquire it's customers. Amazon doesn't have a competing product. And their platform is well-known for supporting multiple competing software products (look at their array of databases for example). And the fact that they are now supporting their own JVM to protect users from Oracle's newly aggressive licensing.

This is, perhaps, exploitation but it seems unlikely they'll kill Elastic ever.