While Ash may be stepping away from the Pokémon anime, it's starting to look like fan-favorite characters Jessie, James, and Meowth of Team Rocket could be staying on for the new series.
The Team Rocket trio first appeared in the second episode of the series, and have been a part of the show longer than any characters other than Ash and Pikachu. While Ash has had many traveling companions over the years, Jessie and James have been a constant fixture of the series. While their "Team Rocket blasting off" bit eventually grew old, the anime has taken to doing more with these characters, often focusing on them while they attempt to do things that don't involve Ash at all, or just living their lives, such as when the team took on part-time jobs in Alola and even earned Z-crystals on their own. The most recent series, Journeys, even had Jessie and James traveling to other locations, taking them out of Ash's proximity.
Continuing that trend, the last few episodes of Journeys have featured a post-credits segment called "Team Rocket Expedition Which Stands by the Evils of Love and Truth," focusing exclusively on the trio, which began after Ash's big victory at the Pokémon World Coronation Series. Jessie, James, and Meowth are sent to Paldea, the new region from Scarlet and Violet, and over the course of three shorts, encounter each of Paldea's starters: Quaxly, Fuecoco, and Sprigatito. They are unable to capture any of them, however, with each short ending in the featured starter getting away.
Team Rocket in Paldea to Stay?
Paldea, of course, will be the setting of the new anime series and home of its new heroes, who were first shown to the world standing alongside the three starters. It's interesting that the anime would break Team Rocket away from Ash at this point and send them to a completely new location just for these three shorts. It seems likely that this is being done to set up a transition away from Ash, offering Team Rocket a chance to encounter the new protagonists and develop a rivalry with them. Bringing over fan-favorite characters like Team Rocket would certainly do a lot to endear the new anime to fans, confirming that the new series still takes place in the same world. Having a constant feature like Pokémon's Team Rocket, even if they aren't the protagonists, helps the overall anime to feel coherent. That doesn't mean that Team Rocket need to appear in every episode, as was often the case in the past. Team Rocket could be used sparingly, showing up only when it makes the most sense to, like when a big incident draws the new heroes' attention.
While it remains up in the air whether Team Rocket (or any aspect of the old Pokémon anime) will continue over to the new Pokémon anime series, they have set up a convenient way for these characters to reappear at any time by leaving them in the same location.