Minor observation:
"If Maven is installed properly, you see information about the Maven installation similar to the following example:"
The illustrated Java version and home is openjdk, which is fine, but different from the pre-req described (which is OpenJ9 JVM).
Right now the Java prereq in this (and other OL guides) is to https://adoptopenjdk.net/?jvmVariant=openj9 This should be replaced with https://developer.ibm.com/languages/java/semeru-runtimes/downloads
Minor observation: "If Maven is installed properly, you see information about the Maven installation similar to the following example:" The illustrated Java version and home is openjdk, which is fine, but different from the pre-req described (which is OpenJ9 JVM).