Benefits of reorging a new table with loaded data?
Db2 for LUW
REORG of compressed tables with RESETDICTIONARY might be beneficial after the initial load, because during the load the table-level compression dictionary is built using a sample of incoming data, which means that if your data patterns are unevenly distributed across the input file the dictionary might be suboptimal. REORG will use a larger sample (if not all of the data) to build the dictionary.
Other than that, REORG after LOAD is unneccesary.
Db2 for z/OS is different because in it every table would have a clustering index (implicitly defined if not declared explicitly), and if your input file is not ordered according to the target table's clustering index, clustering factor after the load will be poor.