Elastic's playbook is almost diametrically opposed to this: they need to prove that they're worth paying a premium for, over AWS' offering. The repo activity clearly shows that they're working on more stuff, building faster, whatever signals you want to glean from that. Change is happening, and if it's good change I can see the gambit AWS is pushing turn into a losing proposition.
The endgame for Elastic is a partnership on AWS, on "equal" terms; license fees, a cut of the profits, the whole shebang. The endgame for AWS is an end to Elastic as a company, but not heavily increased profits one way or another - AWS still gets its cut if Elastic succeeds.
The incentive models aren't equal here, and that's what kills AWS' agenda. I'm not affiliated with either company, so I don't have any inside info, but I have to imagine that Elastic will succeed here in carving out a niche for themselves - unless there's been a silent exodus from the company I understand that these are smart folks building software under, shall we say, extrenuous motivational circumstances. A little stress is good for productivity :)