After the success of Pokemon Legends: Arceus, it seems highly likely that another game in that style is in the works, and if recent leaks and rumors are to be believed, it could be set in the Gen 5 region of Unova. Pokemon Legends: Arceus takes players to a past version of Gen 4's Sinnoh Region known as Hisui where never before seen forms of critters could be found and gives them the option of choosing one of three starters pulled from different generations. With this precedent set, it's safe to assume that a sequel set in Unova's past will also give players this type of choice.