Star Grant Gustin explains why Supergirl and Superman will not appear in the upcoming "Armageddon" crossover event for The Flash. Most seasons of The CW's Arrowverse shows are highlighted by an annual crossover event. This began when it was just Arrow and The Flash, with the "Flash vs. Arrow" episodes, and most recently continued with the "Crisis on Infinite Earths" storyline during the 2019-2020 season. The upcoming "Armageddon" storyline premieres tonight, November 16.
The synopsis for this crossover has an alien threat give Team Flash all they can handle, requiring them to call in some superpowered reinforcements. "Armageddon" will feature Grant Gustin's protagonist Barry Allen alongside heroes from other Arrowverse series, including Black Lightning, Batwoman, Mia Queen's Green Arrow, Ray Palmer, Ryan Choi, and more. This time, "Armageddon" will take place entirely within The Flash, stretching across season 8 episodes 1-5, instead of spreading its storyline across the different shows. However, noticeably absent from the roster are Melissa Benoist's Supergirl and Tyler Hoechlin's Superman.
In a statement to TVLine, Gustin says their lack of inclusion doesn't really have to do with anything in-story. Instead, the filming schedule for Supergirl made it too difficult for the actors to appear on The Flash. Unfortunately, Gustin reports, that also means that there won't be any explanation within "Armageddon" for their absence:
That’s a very good question; unfortunately, I think the realistic, boring answer is because of scheduling, life, Supergirl wrapping up... I wish there was, but no, there’s no acknowledgement of our [hero] aliens.
In the past, The CW's Arrowverse crossover events have often had as many people as they could include from their roster, and this year's is really no different. Although certain storylines omitted some heroes, it was often explained within the story itself, or the omitted hero would have an episode of their own show specifically for that purpose. However, based on Gustin's response, it appears as if there is no in-universe reason prepared as to why Superman and Supergirl are not appearing in this crossover.
However, this does not mean that the show will come up with an explanation in the future. Even though Supergirl just aired its final episode, Superman and Lois is still going strong at The CW, meaning that there could be some in-universe reason later thought as to why the two Kryptonians do not help the the Scarlet Speedster. For now, fans can sit back and watch The Flash season 8 kick off with episode 1 of "Armageddon."
Source: TVLine