Hello,
I make this thread just to share the sprites I have found. Im not sure if the devs can use them, but I tested them on a fan game and works good (The b/w pokemons follows normally)
https://www.mediafire.com/file/f4zo843o4bkmgwe/Follow sprites.rar
Hope this will be useful, I know everyone wants bw pokemons following.
(Just for those who dont believe in what Ive upload, check this fan game)
https://pokemontitan.wordpress.com/
It has all the sprites of all pokemon gens implemented.