Important to note though that they are not retroactively changing anything. The license for old code was and remains Apache and can be used under those terms.

Important to note though that they are not retroactively changing anything. The license for old code was and remains Apache and can be used under those terms. Elastic are of course entirely entitled to change the license to whatever they feel like, including closing the source entirely for future development. But they made the choice at an earlier stage to release the code under a permissive licence - that was a choice to allow others to do what they want with the software, not just “what you want so long as it doesn’t infringe on our business model”. They are free to change their mind on that, but it’s not like it’s an unexpected, unfair, or unpredictable outcome.