The Carter Hall mentioned by Tina is this Earth's counterpart to the father of Hawkman's incarnation of the same name on Earth-1.
- Alternately, he's Katar Hol. Since he was the then-current Hawkman.
Barry eventually gets back together with Iris West and meets her nephew Wally.
Wally West looks like Michael Rosenbaum, and becomes his sidekick Kid Flash. The heroes killed in The Stinger promoting Elseworlds were this world's Justice League
With the exception of Leonard Wynters of course. The Flash was The Mentor to these heroes, who consisted of;- Stargirl, who resembled her Earth-1 counterpart, but was a contemporary youth.
- Huntress, who resembled her Earth-1 counterpart, but was nobler and less bloodthirsty. She may have been Helena Wayne instead of Helena Bertinelli, the daughter of the deceased Batman of Earth-90.
- Firestorm, who is Jefferson "Jax" Jackson, and is the original Firestorm on Earth-90. Instead of Martin Stein, he fused with either Ronnie Raymond or Jason Rusch.
- John Diggle, who might have had a different codename. He was hired by Earth-90's Oliver Queen to train him in things outside of archery to become Green Arrow.
- Jesse Quick, who is a Legacy Character to her father, Johnny Quick, one of the few doppelgängers of Harrison Wells who isn't named Wells.
- The Ray, who resembled his Earth-X version. He could have not been native to Earth-90, but still and Alternate Self to the Rays we have already seen.
- Citizen Cold, who was Ray's boyfriend. He was the rebellious son of Leonard Wynters who aimed to be a good guy.
- Hawkman, the Earth-90 version. This one is the son of Carter Hall.
- Hawkgirl, the Earth-90 version. This version was a Thanagarian spy who defected to Earth.
- Green Arrow, who resembled his counterpart from Smallville.
- Or he could be Arrow's son Connor Hawke/William Clayton.
In this universe, John Diggle's relationship with his stepdad turned out better.
Hence taking his last name Stewart. In this universe, Gorilla Grodd is actually a yeti.
The last living Yeti that somehow developed super-intelligence and gained Psychic Powers, and became a Super Mob Boss. Similar to Silver from Ninja Turtles: The Next Mutation, which would have been more feasible to do in early 90's TV than using an actual gorilla and CGI hasn't reach the level of realism yet. Earth-90 was reborn at the end of Crisis on Infinite Earths (2019)
Though it wasn't seen during the montage at the end, its possible, even likely, that Earth 90 too was brought back as part of the new Multiverse. In this reborn world, Barry Allen is alive and well, and probably enjoying a peaceful retirement with Tina McGee.