>>32175350It was cut by the either the censors or the executives. They dubbed it when they first dubbed the movie, as evidenced by the commentary track talking about the cloned starters having the same markings as their evolved forms, but you don't see the cloned starters outside those scenes.
I think it might be because they wanted a G rating, but that scene of a little girl dying pushed it up to PG, so they cut it. Mewtwo Returns was either unrated or it was PG anyway, so they were able to put it on that DVD.