Right, you see the past in flashbacks. However you never get to witness the past in its entirety. To me, that's the only direction they can go in this series. They can't do a sequel because Spike's dead. And they also can't do a movie that takes place during the series because Cowboy Bebop: The Movie already did that. Plus whenever they do a live action anything, it always takes place before the series actually starts.
But yeah, you're right, that would mean that you wouldn't see Jet, Faye, Edward or Ein. That sucks because Ed is my favorite character.