Electivire is still a good pokemon, although it isn't stronger than Lucario, purely because Close Combat outdamages ThunderPunch. Electivire's ability WOULD be great, but unfortunately the electric pokemon/moves he switches into are often paired with other moves. For example, a Timid LO Zapdos's Heat Wave can manage a 2HKO provided Stealth Rock is in play. Rotom-A carries Will-o-Wisp / Reflect, and Shadow Ball hurts too. He's great at switching into Blissey, but he doesn't enjoy Toxic too much. Overall, the metagame is just too fast for Electivire to be as efficient as other sweepers. Whether it is +Speed base 115's running Scarfs, or powerful priority attacks from the likes of Scizor(Bullet Punch 2HKOs after SD), Lucario, and Mamoswine, the lack of opportunities to switchin are beat out the pros of his ability/movepool.
As for GyaraVire, I think right now is possibly the worst time to use it. People are running Gyarados + SpecsJolt all over the place, so people are being careful when they throw electric moves around.