>>42563155unironically because it's too much work
you would need to animate 100+ pokemon for it
following pokemon are way more likely but gamefreak can't optimize for shit so we can't get that either
i'm actually pretty sure following pokemon were cut from gen 7 at the last minute because of how often characters talk about the first pokemon in your party during cutscenes, as if it was present
not to mention hau's starter follows him around
if gamefreak had been allowed to make it an N3DS exclusive we may have gotten them