Pick & choose

[Bored at 3:00AM]

To get it somewhat back on topic...

What the OP is referring to is 'head-canon'.

I still do this with the JSA.
If I read a story that fits within the context of the pre-Crisis Earth-2, even with a few minor alterations, that's where it goes.
If it doesn't I ignore it or treat it as an alternate universe version.

For Me, Earth-2 wasn't destroyed during Crisis.
In my head-canon, it was just removed from Earth-1's reality. And Earth-1 compensated by 'creating' Earth-1 versions of the Earth-2 heroes present in its reality during the Crisis.
The Atlantean Power Girl, the Bertinelli Huntress, the changes made to Dr. Fate regarding hosts... were all done by Earth-1's reality trying to 'make sense of it all' in a universe with no Earth-2.

Meanwhile, Earth-2 continued to exist, similarly cut off from Earth-1.
There's a possibility that new heroes were created on Earth-2, as well, to fill the void created by the removal of Earth-1.
The Infinity, Inc. team took over as the new JSA and they added more members as time went on.
These new members would be both legacy heroes and new heroes making their own names, because the JSA (on their Earth) is just as big as the JLA or the Avengers. And always would be.

I love this idea!

[Lightning Rider]

Facts are facts. You can ignore story points but doing so is childishly ignoring facts.

You're ridiculously obstinate.

When a fictional property's cannon includes a narrative fact someone doesn't like, it's not childish but delusional to assert that it didn't happen. Nobody is doing that here.

But fans can choose to ignore the narrative point in their internal conception of the character if they feel it betrays something essential about it. This isn't exclusive to superhero comics.

When it comes to characters this vast and complex, it's almost impossible to distinguish these facts with a hard line anyway. Identities and personalities and events from different eras overlap and bleed into each other until everyone has their own personalized synthesis of who that character is in their head. And that's not a bad thing.

[Lightning Rider]

"Jimmy, I don't know how many times I gotta tell ya, there ain't no such thing as a canon, and anyone who says differently is just tryin' to sell you something."

Lederman! RIP