Pretty much. The best description I've heard is that 'All Star' is about the "no-Crisis Superman." Not the "pre-Crisis," not the "post-Crisis," but the "no-Crisis." ie, there was no Crisis, and here he is, all of them, 20 years later.
"Crisis? WHAT Crisis?" :wink:
So if the Crisis never occurred and we're "Twenty Years Later", does that mean we haven't seen Supergirl yet because she's too busy as Governor Linda Danvers of Florida? :wink:
Or perhaps a Crisis DID occur in the All Star Universe, but the Byrne Reboot never happened? (Of course, if we see an older Kara Zor-El or an "All Star Flash" featuring BARRY ALLEN then this hypothesis goes BANG.)
Hmm...