Jimbei isn't playable in One Piece Odyssey, as he didn't officially the crew until after it started development.
Yamato is a popular One Piece character who was introduced near the end of the Wano arc. Despite his late appearance, he proved to be popular with the audience, outpacing many of the established of the Straw Hat Pirates in the latest official popularity poll. There was a lot of evidence to suggest that Yamato was going to the Straw Hat Pirates, including a chapter ending with Yamato expressing that desire. There was a sudden swerve, however, and Yamato decided to not the crew, leading to a backlash from fans. A scene in a later chapter was added to try and flesh out Yamato's reason for not ing the crew just yet, which felt like damage control following the response.
One Piece Odyssey will launch in 2023, so the developers have had the chance to monitor the response to the manga and One Piece Film Red. The harsh response to Yamato not ing the Straw Hats has died down somewhat, especially following several fantastic chapters that have finally moved the story away from the overly long Wano arc. It's likely that Yamato will return in the future, even if it's just as an ally during the final arc of the series, but there's a chance he could appear in another medium.
One Piece Odyssey DLC Can Have Yamato The Crew
The developers of One Piece Odyssey confirmed during the Tokyo Game Show 2022 that the game will receive post-launch DLC, as well as outfits that will be tied to specific editions of the game. One Piece Odyssey's playable character roster includes all of the of the crew, save for Jimbei, but the DLC could add him further down the line. The DLC content also has the chance to add Yamato to the list of playable characters, making him a part of the crew during their adventure on the island.
One Piece Odyssey is a turn-based RPG, which means that there isn't as much work involved with creating move sets and playstyles for different characters as there is for an action game. This means that the DLC could easily add different characters to the team, such as Jinbei and Yamato. Bandai Namco has confirmed that One Piece Odyssey will have a story-based DLC in the future and the fact that it's a non-canon game means characters from Wano can be added without needing to refer to the timeline. Yamato fans might be disappointed that he didn't the crew, but One Piece Odyssey can make it up by making him part of the crew in the game's DLC.
