Originally Posted by
K. Jones
Batman, Wonder Woman (whose use and absence in this story is conspicuous as well), and Aquaman. Specifically.
I've always found it fascinating - Batman's continuity, though chopped, does remain incredibly consistent, and was even persistent and notably thus when the New 52 happened and everything got rebooted but the Batman run effectively continued virtually identical to what was going on already ... just in a timeline that made zero sense. (Tangentially, because its relevance isn't really being showcased in any way in Doomsday Clock, the same is true of Dick Grayson.)
This contrasts insanely to Aquaman - who has existed parallel to Batman for almost the whole time as a Golden Age Justice Society guy who quietly carried over into the Silver Age and only then started getting continuity tweaks. While Flash and Green Lantern and Atom got total revamps for the Silver Age, Aquaman just sort of got fleshed out a little and brought up to date with Silver Age concepts like the girl, the sidekick, and the secret origin. Unlike Batman, whose "spot" on the Justice League was never really mentioned again except in Earth-2 stories ... Aquaman was given an ersatz GA version in the form of Neptune Perkins, the inferior knock-off. Contrast that with Hawkman. Hawkman fits into a similar role as Aquaman as well, except even though his Silver Aging turned him into a space cop from Thanagar, over the years has been (insanely) reconciled so that his ersatz GA version is ... just another version of the same character.
The Trinity's relationship with the Golden Age is fascinating stuff. And like Star Trek, I tend to believe there isn't really a "trinity", but rather a "trinity plus". (Montgomery Scott is obviously the "fourth musketeer" in Star Trek, and I believe you can probably view Dick Grayson, Aquaman, and maybe Hawkman in that sort of position in the DCU as well. But in this story, Dick, Arthur, and Carter are all just part of the big superhero ensemble, and aren't separated back on Earth like the Trinity are. But it's probably noteworthy that they're there, in the superhero armada ... and paired with their respective Silver Age female counterparts (Batgirl, Mera and Hawkgirl) and Silver Age Barry and Hal, too.
Also got to point out that Captain Atom got a direct one-on-one with Manhattan in this storyline, and The Question, Blue Beetle, and Nightshade are there, too - so while downplayed in their role we're also seeing "THAT" universe interact. As well as the Shazam Family. Two more universes, now subservient to the main metaverse.