Mobile Suit Gundam producer Studio Sunrise announced an initiative in 2018 called the UC NexT 100. This project was stated to consist of anime works depicting events further in the Universal Century timeline than other recent projects, which have tended to focus on the era surrounding the One-Year War.
This project is intended to bridge the gap between the past and future of the timeline, further fleshing out the events taking place in between and beyond the over 50-year gap between Char's Counterattack and Victory Gundam. There are many possibilities for anime in this wide timeframe, and since relatively few existing projects take place in this era, fans are speculating on what characters, unseen events and new mobile suits may be set to appear.
So far, only the movie trilogy adapting franchise creator Yoshiyuki Tomino's Mobile Suit Gundam: Hathaway's Flash novels has been announced, with the first movie released and the second's date currently unknown. It is likely the trilogy will be completed before any solid info about the next project phase is made public. The most recent project in the UC timeline is Mobile Suit Gundam: Cucuruz Doan's Island, but this film takes place during the One-Year War and is therefore not considered part of the project. Sunrise will likely focus its efforts on the alternate-timeline series The Witch From Mercury for the foreseeable future. However, once the time comes for Sunrise to unveil the next project in store, there are three likely scenarios: an adaptation of a manga or light novel taking place during this time period like Hathaway's Flash, a side story for an existing anime, or a completely new project depicting unseen events between or beyond the events that are already established.
For the first possibility, there are many manga and novels that fill in the gaps between anime projects, although few left that Tomino himself worked on. One of the most climactic is Gaia Gear, a novel project depicting events past U.C. 200 where a memory clone of legendary pilot Char Aznable leads a resistance against the Earth Federation once more. Unfortunately, this series leads to a rights schism between Tomino and Sunrise; while it was later resolved in a way that allowed the two to continue their business relationship, the story of Gaia Gear itself may remain unadapted because of this.
A more likely candidate for an anime adaptation is the spinoff manga Mobile Suit Crossbone Gundam. Written and illustrated by Yuichi Hasegawa from a story concept by Tomino, this manga is closely related to the film Mobile Suit Gundam F91 and picks up on unresolved elements of the story. It is an ideal fit in the timeline and has remained popular with franchise fans. It also earned itself a series of sequels, including Dust, X-11 and Karras.
The next possibility is a side story to an established work. Unlike Crossbone Gundam, which takes place over 10 years after F91 and includes many new elements that help it stand alone, a side story would be linked closer to the time period of the original and center around major characters from it. The Gundam Narrative film works in this manner for Gundam Unicorn; while it is an adaptation of the UC: Phoenix Hunting novel written by Unicorn author Harutoshi Fukui, which is sometimes considered the 11th novel in the Unicorn series, it focuses on new characters and picks up on a leftover plot thread instead of directly continuing the adventures of the characters of Unicorn, featuring a few of them in cameos or supporting roles.
These stories could similarly adapt established stories; F91 and Victory both have multiple side story manga depicting smaller events around the timeframe of those works. However, they could also be wholly original stories with endless possibilities, depicting the hellish nature of war from a new perspective. The potential associated with these options is endless, closely linking them with the final major possibility for the future of the UC.
The vagueness of the concept of a wholly-original story taking place in the future of the Universal Century makes this the most intriguing possibility. As mentioned earlier, this could manifest itself as a sort of side story focusing on unseen events occurring within the timeline of works like F91 or Victory, fitting into these eras like how works such as The 08th MS Team and MSG Thunderbolt take place during the same year as the original Mobile Suit Gundam anime. These could also include unrevealed character backstories or even the events surrounding surviving characters from one series meeting the protagonists of another, like how much of the cast of Victory reappears in Crossbone.
However, this could also manifest as a brand-new major story event. One that takes place between F91 and Victory could depict a brand-new conflict or fill in gaps left by the series, such as fleshing out the rise of the Zanscare Empire and the relative absence of Zeon's influence by the era of Victory. If it takes place after Victory, it could depict anything; a resurgence of Zeon or a corrupt Earth Federation faction like the Titans of Zeta Gundam, a post-war slice-of-life story somehow involving a Gundam, or even a story that links with works like Turn A Gundam or Reconguista in G, two Gundam anime that are stated to take place thousands of years after the Universal Century ends. It could even reference the much-maligned live-action G-Saviour, though this is about as likely as Gaia Gear receiving an anime adaptation.
The possibilities for the next installment of the UC NexT 0100 project are endless and not limited to the three major possibilities discussed here; while it is currently unknown what it will be, Mobile Suit Gundam fans eagerly await the next announcement even as Hathaway 2 looms on the horizon.