Just heard back from McAfee. It seems they are still progressing with an EOL date of Sept 2018 for ePO 5.3.3. (Seems a waste to only support that patch level for a year, but, so be it.) The are now recommending moving forward to ePO 5.9, Patch 9 (5.9.1?) although Patch 1's RTW date is not yet known - the word was, if we can 'wait for it', 'wait for it'.
Download the new ePolicy Orchestrator (ePO) Support Center Extension which simplifies ePO management and provides support resources directly in the console. Learn more about ePO Support Center