Legends Of Tomorrow's Seattle 2042 Explained
It was in the third episode of Legends of Tomorrow's third season, "Zari", that the dark world of 2042 Seattle was first revealed. Though the exact details of how it happened were never discussed, it was explained that the United States had devolved into a fascist society sometime after metahumans were outlawed in 2021. This also led to religion in all forms being outlawed and ARGUS - a covert anti-terrorism organization in 2018 - becoming the main police force of the new regime.
The episode also introduced the character of Zari Tomaz. A hacker and resistance fighter, Zari was wanted three times over by the regime that ruled the United States in 2042. This was because she was a devout Muslim, a rebel fighter, and she possessed a magic totem (later revealed to be the lost Air Totem of Zambesi) which granted her the power to control the wind and fly.
Zari became a powerful addition to the ranks of The Legends, but she rankled against the team's rules against using time travel for their personal benefit. However, a relative eternity stuck in a time-loop drove home the point to her that trying to change history was incredibly risky and not easily accomplished. Still, this hasn't stopped Zari from finding creative loopholes to spare Helen of Troy the sad existence of a trophy wife in 'Helen Hunt' or saving a young widow from being burned at the stake in "Witch Hunt".
The Legends of Tomorrow season 4 premiere, "The Virgin Gary", featured a scene where Zari lamented that for all her power she could not use her ability to time travel to save her family from being killed by the government in her time. She also discussed how she was afraid that doing something to prevent her future from occurring might undo her existence and every act of good she had performed to save countless lives in her time as a Legend. This theme came up again in other season 4 episodes, in relation to Zari talking to other characters about the desire to change the past to prevent something bad from happening. Given that, it seems to be foreshadowing that Zari's life is about to change in a fairly major way.
The Flash's Central City 2049 Explained
The Flash season 5 premiere picked up immediately where the fourth season ended, with Barry Allen and Iris West meeting their daughter from the future. Introducing herself as Nora West-Allen (aka XS), the young time-traveler claimed to have become stuck in 2018 and unable to return to her time, about 30 years in the future. This was later revealed to be a lie and the young woman revealed that she had come back in time to meet the father she never knew, because Barry Allen disappeared following a crisis of some kind in 2024.
The fact that The Flash vanished at some point in the future was established by a newspaper from 2024 in the very first episode of The Flash, but Nora added a few interesting wrinkles regarding the future of the Arrowverse. She revealed a newspaper from 2049, which discussed the 25th anniversary of the battle in which The Flash disappeared and how The Flash was never seen again afterward. She also mentioned the creation of a Flash museum which taught her almost everything she knew about her father's exploits as a superhero and one brief flash-forward showed her visiting the museum as a child in 2032.
While it is possible that the anti-vigilante future of Star City 2038 is part of the similarly dark world of Seattle 2042, it seems all but impossible to reconcile Nora's future with either of the realities seen in Arrow or Legends of Tomorrow. It seems unlikely that Central City would be allowed to have a museum honoring their greatest superhero in 2032 if metahumans were outlawed nationally in 2021. This also raises questions about how Iris West would be allowed to write two articles detailing the exploits of superheroes favorably in a public newspaper in 2024 and 2049 respectively.
One possible answer may be that Nora's traveling back in time has formed a divergent timeline akin to Flashpoint and all of The Flash season 5 so far is taking place within a paradoxical timeline that has yet to be refitted into reality. Another possibility is that Nora is lying about her future - something she has already tried to do several times over the course of the season and which she was seemingly caught doing again by Sherloque Wells in regards to why she chose to expose herself by helping her father destroy the STAR Labs satellite. Hopefully, the events of the 2018-2019 season will eventually come to reconcile these conflicts between the various futures of Arrow, Legends of Tomorrow and The Flash.