The only episode, except for "Alive!", where none of the original Justice League members had a speaking role (though J'onn J'onzz did appear).
When detailing her history with Wildcat, Canary mentions that he also trained many other members of the League. One of those members was a young Bruce Wayne.
The super villain contestants of the Meta-Brawl include: Amygdala, Atomic Skull, Bloodsport, Electrocutioner, Evil Star, Hellgrammite, Sportsmaster, and Tracer.