The DFW-Hawaii flights are treated like any other long haul widebody flight. So if you are getting ticketed in Premium Economy, you should get all the published benefits including enhanced meal service and other amenities.
https://www.aa.com/i18n/travel-info/...um-economy.jsp
Incorrect. Although AA sells Premium Economy as a separate class of service on DFW HNL/OGG flights, the meal service is nothing like on international PE. Both Main and PE on these Hawaiian flights will receive a tiny salad, equally tiny piece of cake (which you can literally eat in one bite), and a cold turkey sandwich on AA whilst on DL and UA flights with a proper PE cabin get hot meals.