You can call any decision you want crazy, but it's not relevant in a matter of trademark, and they talked about this at the time of the original license change. The word "Elastic" isn't enough on its own. In contrast Amazon was literally offering a product identical to theirs (quite literally) that was also using the exact same name "Elasticsearch".

If Elastic the company sold a product called "Elastic Amazon EC2" and it was an API compatible copy of EC2 cloud compute, you can reasonably assume that Amazon would be pissed off about it.

It might not be sufficient to trigger trademark violation, but that doesn’t stop it being a dick move.

Edit: As was Amazon's choice to offer a service named that once Elasticsearch was established, to be clear.