[quote=@LuckyBlackCat]
[@Balthazar007] Yep, that reward system sounds good. And if Alolan Pokemon are available in the wild, does this mean Pikachu, Cubone and Exeggcute can evolve into their Alolan forms? If so, how do we determine this? Is it random in-universe (meaning we can choose), or is there some kind of item that makes them evolve differently?
[/quote]

The answer to that is already in the Manual. Pokemon>Evolution. No item, just make it make sense, like some rare situation that causes the evolution. Creative freedoms.