Why is the old /usr/lib/jvm/JAVA directory not removed during an update?

Issue

• When java is updated (yum update), the old JAVA directory is retained:

# cd /usr/lib/jvm
# ll
drwxr-xr-x 3 root root 16 Jul 31 01:44 java-11-openjdk-11.0.10.0.9-1.el7_9.x86_64
drwxr-xr-x 8 root root 90 Jul 31 01:42 java-11-openjdk-11.0.11.0.9-1.el7_9.x86_64

Yet on another box when java is updated, the old JAVA directory is removed:

# cd /usr/lib/jvm
# ll
drwxr-xr-x 8 root root 90 Jul 31 01:42 java-11-openjdk-11.0.11.0.9-1.el7_9.x86_64

• Why is sometimes the old /usr/lib/jvm/JAVA directory removed when there is an update, and sometimes it is retained?