Thomas will stay in the present.In the source material, Thomas stayed in the present because he had a secret mission to carry out. Here, he could choose to stay because of his friendship with Jessica, which could parallel how Supergirl chose to stay in the future to stay with Brainiac 5. Plus, Thomas would take Simon's place as Jessica's platonic life partner (with possible Ship Tease).
- Confirmed... in a way. He dies in the present.
Miss Martian is a clone of J'onn or another Martian.Cadmus tried to pull a Superboy/Galatea on J'onn by taking a sample of him or Martian cells still left on Mars, which resulted in Miss Martian. After Cadmus was decommissioned, they eventually revealed the existence of Miss Martian and let her join the League.
Miss Martian is also a survivor of the Martian-Imperium War.Like in her comic origin, she was sent away to the Vega system, and at some point, she came to Earth.
Jessica will grow out her hair.
- She had long hair that she ponytailed in the flashback of her backstory, but that's it.
- If Thomas's "flashforward" of the museum means anything, Jessica is apparently remembered more for when she had short hair. Although, John has his original JL look instead of his JLU look, unless he went back to his old look after JLU. Kyle has a new design that he seems to be more remembered for as well.
The Fatal Five want Jessica because she has something to do with the Emerald Eye.The Emerald Eye of Ekron's backstory is still a mystery in the comics, outside of it being the literal eye of someone named Ekron and being created by the Green Lantern Corps.
- Jossed. They want her to help them reach the central power battery on Oa.
This film will start a line of animated movies that take place in the DCAU....although that honor technically belongs to Batman and Harley Quinn (or Justice League: Gods and Monsters?)
Simon isn't Adapted Out.At the end of the movie, Jessica could meet someone who introduces themselves as Simon Baz. Alternatively, Simon is introduced in a continuation.
- His chances are looking pretty bad, since he doesn't appear in the museum chamber of Green Lanterns with John, Kyle, Hal, Guy, and Jessica, who are 5 out of the 6 main Green Lanterns in the comic.
Other members of the League will return at the end of the movie after the Fatal Five are defeated as a Brick Joke.
The statues in the future Hall of Justice are tributes to all of the League members that left.Huntress and Captain Marvel are there, despite no longer being League members. Batman will also leave the League after Batman Beyond: Return of the Joker. Which raises the question as to what causes Zatanna and Doctor Fate to leave. Zatanna's departure could be a reference to her departure from the League in Justice League of America during Blackest Night, and Doctor Fate's departure could have something to do with Nabu.
- Counterargument: If you consider the comic continuation canon, then where are the statues for Diana (left to stay with in the Justice Lords timeline), John (Lantern ring got confiscated and forced into retirement), Shayera (joins John in retirement), Flash (disappears into the Speed Force), Vixen (killed by Shadow Thief), Hawkman (killed in the Thanagarian-Rannian war)?
Simon can still appear.Due to the events of the movie (especially since Batman, Miss Martian, and Jessica now know information about the future), this can alter the timestream, resulting in the recruitment of another Green Lantern that originally wasn't meant to exist in the original version of the timeline.
The Green Lantern Corps is extinct in the future because Hal gets possessed by Parallax and kills all/almost all of them.
The Legion of Super-Heroes knew that Thomas was going to die.