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.