These Pokemon plush were originally made in Japan under the name 'Pokemon Fit', and were later released in the U.S. as 'Sitting Cuties'. The plush on this website specifically are from the U.S side. Both regions have the exact same plush, though, no differences.
Gens 7, 8, and 9 aren't out yet, but they will likely be out in the next few months; it takes them a while to come out with new generations, so be patient.
Not to worry, because on our contacts page, you can tell us who your favorite Pokemon is, and we'll likely have it on sale, so if you can't find your favorite Pokemon, just contact us, and we'll get it for you; as long as it's in Generations 1 through 6!