The HBase's HMaster port number conflicts with Hadoop kms port number. Both uses 16000.
There might be use cases user need kms and HBase present on the same cluster. The HBase is able to encrypt its HFiles but user might need KMS to encrypt other HDFS directories.
Users would have to manually override the default port of either application on their cluster. It would be nice to have different default ports so kms and HBase could naturally coexist.