My experience is that EUA ignores reward tickets, last month traveling with my wife on F/C reward tickets, we were confirmed in coach/waitlisted for first for one segment. Elites were upgraded before departure but we stayed in the back.

Later I called OnePass to inquire about priorities for open F/C seats at departure, was told that we should have been given the seats before passengers were upgraded. They gave me 5,000 OnePass miles for each of us for compensation.