Honestly, I would rather have them dead of old age than have them back but be neutered by having their history as part of the DCU removed. It would basically be the New 52 all over again: we'd have a guy who looks like Jay Garrick back, but not the Jay Garrick. Just like we had a guy who looked like Superman, but didn't feel like the real Superman.
Plus, if the JSA hadn't been continually active, that just means that a bunch of other fan favorite characters, like Jade and Obsidian and Jesse Quick would never come back. I mean, does anybody think that that's a good idea?