RHV 4.3 requires EAP 7.2, but unfortunately EAP made a backward incompatible change, so EAP 7.2 is no longer included in jb-eap-7-for-rhel-7-server-rpms channel, but RHV administrators needs to subscribe jb-eap-7.2-for-rhel-7-server-rpms to be able to upgrade from 4.2.z to 4.3 or install new 4.3.
Updated (but not yet published) documents: 4.3 Installation Guide 4.3 Upgrade Guide 4.3 release notes (4.2.7 section) 4.3 Java SDK I can't provide links because access does not yet seem to be available for the preview/staged 4.3 versions in Pantheon.