I feel the most strategic changes in java9 are about cloud, such as
- Docker container
- memory footprint reduction
https://qconsf.com/sf2016/sf2016/presentation/java-se9-cloud.html is a 2016 article
When cloud computing becomes an even bigger driver than it is today, some legacy technologies will gain mind-share while others will lose mind-share. Java 9 team wants to be a winner.