I dont see much point in why they should, I'd rather them just bringing out more new games. Anyway, I highly doubt that they will release pokemon green...but my cousin once owned a catridge with a load of pirate games which included pokemon green! for some reason all the pokemon had weird names- i remember pidgey being called bichon for some weird reason. All the sprites did look...different.
There were a load of other fake pokemon games (and I mean fake!)
I remember one which was called pokemon go! go! go!- it was so stupid- on the intro screen it just showed clips from the japanese GSC pokedex- then it moved onto the game which was where you controlled this rat-like thing which looked a lot like a tall pikachu-bunny rabbit thing. Hideous. *shivers*
EDIT: I almost forgot! This is my 200th post! yay!