Assassin's Creed Infinity - a rumored live-service title - being in the works. Considering the end of Valhalla, however, it may be safe to assume that Desmond, the original protagonist of the first few games, will be making a return.
[Warning: Major spoilers for the ending of AC Valhalla below.]
Assassin's Creed Valhalla ended off with some major ramifications to the overall storyline of the series. Layla, the modern-day protagonist of the recent trilogy, became trapped in an Isu supercomputer by Basim, where she meets a man named the Reader. The Reader, who is voiced by Nolan North, the original voice actor for Desmond, is trying to find a way to stop a cataclysmic event from ending the world by analyzing different timelines. Layla offers to help her, abandoning any attempts to save herself and hinting at Basim leading new Assassin's Creed games both as a historical character and as one in the modern-day story.
Although Desmond was presumably killed off at the end of Assassin's Creed 3, there is a good amount of evidence hinting at his possible return in future games. A majority of this evidence can be seen in Valhalla, which can also be used to explain what exactly happened to Desmond after the events of Assassin's Creed 3. Nolan North being chosen to voice the Reader is likely not a coincidence and could be the beginning of the 15-year-long franchise returning to its roots.
Desmond Miles Could Be Assassin's Creed Valhalla's Reader
At the end of Assassin's Creed Valhalla, players were introduced to a new character known cryptically as "The Reader." This character had the same body shape as Desmond Miles and was voiced by Nolan North, who also voiced Desmond in the original games. The Reader could possibly be Desmond's consciousness, trapped in the net of the Isu supercomputers. Desmond died in Assassin's Creed 3's ending after he touched an Isu orb, shaking violently and even glowing similar to how the Reader looks in Valhalla.
Years after his sacrifice in Assassin's Creed 3, Desmond could be the Reader seen in AC Valhalla, utilizing the power of the Isu to stop another apocalypse from occurring. It was also confirmed in the Assassin's Creed comics that Desmond's body was recovered by Abstergo for some shady experiments. Using the healing power of the Staff of Hermes - now in Basim's hands - Abstergo or even the Assassins may be able to bring both Desmond and Layla back to life in what could be Assassin's Creed's last ever trilogy.
Assassin's Creed's story has covered multiple eras and many twists. After the events of AC Valhalla, the series could pull off its biggest twist yet by featuring the return of its popular modern-day character, Desmond. It would make sense in the overall storyline and his return could be used to bring the series back to its roots. Desmond's return to Assassin's Creed could prove to be a welcome one for many fans of the franchise, and given the hints that Valhalla provides, it could be more likely than not.