>>26926631They're made as resources for hacks, but I don't think they were made for any specific hack. It's also front-sprites only, no backsprites, so anyone using those Pokémon would have to find some backsprite.
While I'm posting general resources, Kalos is like 99% done, though the project died before a few backsprites got made and some of the sprites were meant to be replaced by better ones later (it was a group project on a Spanish site)