And remember that Jynx is banned in the dub. Rujuura (Jynx in Japan) remains in the original version. They're not showing Jynx in the dub due to her skin staying black. Main reason we haven't seen Porygon 2 is because Prof. Akihabara's the only person we've seen with two Porygon. If Pory 2 were introduced, he'd have to be reintroduced along with his two Porygon, which could cause disasterous memories.