I wouldn't be surprised if the Pokemon 2019 is set on Kanto but the setting is like 20 years after the original RBY.
They will add the nu-evolutions of gen1 pokemon like Steelix, Tangrowth, Slowking, Rhyperior etc, they'll add alolan forms which are exclusive to the safari zone, and the new pokemon will entirely be gen1 evolutions like maybe a Farfetch'd or Mr.Mime evolution. Most of the gym leaders are now middle aged and maybe Blaine and Agatha will be dead so they get replaced by their children or something like how Janine replaces Koga in gen2.
But other than that it'll be mostly the exact same game as RBY.
