Didn't SAG's contract renegotiation a few years back end that? I thought now it was business class only. That was the impetus for United killing first class on their LAX-NYC service.
It's also rumored that United lost a lot of entertainment business when they killed their LAX-JFK service and moved everything to Newark. AA still flies a 3-class plane on LAX/SFO-JFK with lie-flat seats in business and first.