By this map from the military site available to the public (https://cnrh.cnic.navy.mil/Installations/JB-Pearl-Harbor-Hickam/About/Map-of-JBPHH-MWR-locations/) the land marked is considered part of Joint Base Pearl Harbor Hickam. And from the Hawaii Statewide GIS Data (if you look up the various tables and cross reference the land usage), the land use is marked as military as well. If not those sites, the map layer on ID called USGS topographical map surrounds the military areas in a thick red highlight as well (though the map might be on the older side) 

Even if it is not part of the base, you would split the relation rather than change the entire relation value. No source was mentioned on the changeset either which points to the source which mentions why it would not be considered part of the military base either and even looking at satellite imagery, those areas are fenced off and requires going through a checkpoint to enter those areas which still points it towards being part of a military base and even if not, used for military purposes (recreation or residential land uses dedicated only to military personnel still counts as military landuse)