After spending some time this weekend updating our Windows FileMaker Server 15.0.2 servers to 15.0.3 and migrating another v14 to v15, we're just picking up the pieces as far as Java goes.
It looks as if the FileMaker installers don't update Java, but adds the new version. All the 15.0.2 to 15.0.3 updates retained the original Java 8 update 110 and added update 111.
The v14 server included Java 8 update 77, update 110 and update 111 resulting from the original v14, the v15 installer then the 15.0.3 updater. Oracle's recommendation is that older versions of Java are not retained for security purposes, so these had to be removed manually from Programs and Features.
The above has been prompted from one of our smaller configuration's server scripts falling over with error 757 'FileMaker Script Engine (FMSE) process is stopped' and we believe from past experience that multiple Java occurrences can be a factor in this.
So, if running FMS 15 updates on Windows, do check Control Panels Programs and Features for older versions to remove.