Before Bungie became known for Halo and Destiny, it launched a critically and commercially successful game for the Apple MacOS, Marathon, in 1994. Marathon later got two sequels in 1995 (Marathon 2: Durandal) and 1996 (Marathon Infinity). Due to its success, Microsoft tapped Bungie to work on Halo for its then-new gaming console, Xbox. Now that Bungie is a part of the Sony umbrella and has expanded many times over the years, it has all of the resources to work on multiple projects at the same time.
If we believe the rumors, one of Bungie's upcoming projects is a reboot of the sci-fi shooter series.
According to Insider Gaming, Bungie's Marathon reboot is already in a pre-alpha state and will turn the seminal shooter franchise into a squad-based, team-extraction-type multiplayer title. Jeff Grubb later corroborated the rumors, adding details that the game is a "free-to-play live service title" with "highly customizable" characters and is an "authentic Bungie FPS experience."
With both Grubb and Henderson reporting the same thing, an official announcement is all a matter of when and not if.
Having said that, even without these rumors, most were half-expecting Bungie to explore new IPs after the Sony acquisition. Its experience with live-service titles is one of the reasons why Sony has a lot of projects with live-service elements planned through 2026. If Bungie is not the lead developer on a game, it's likely that Sony will leverage its expertise to ensure everything is smooth sailing. Besides, Bungie had already confirmed in 2019 it's working on a new IP that will be out by 2025.
TLDR; if you connect all of the dots, there's a fat chance that Bungie will launch a Marathon game in 2025.
The only question now is, is this Sony's answer to Call of Duty becoming an Xbox exclusive?
In other news, Bungie is working on several Destiny-related projects such as a mobile spin-off and an animated show. It's also believed that a third-person competitive action game is in development at Bungie.