people who are good at codeing like me can go in and change that to better moves i.e. i can go in to my save file and change the move and how many of that move my pokemon can have say my Pidgey have Gust i can change that to whirl wind or something like that and give it 1000pp on the move.... to put Missing no in the game would be tougher to do it can have with the people doing you just have to find the pokemon code for him and do what ever you want with him you could change your pokemons lvl from lvl 5 to lvl 1000 or what ever soooo i still say it can happen if the modders for the game work hard on it like they did the gamemodes