Being a silent protagonist, he's not really supposed to say much aside from "Yes" and "No," and being from a country that parodies the United States, he shouldn't be speaking Engrish, but the FRAHS... it's very peculiar. Kirby got it right in Melee, but this time, he says "Frash." The voice actress is the same person for both characters, if I'm not mistaken. Why did she decide to do it half right in one game, then replace the correct voice clip with a worse one just for Brawl? Or did Sakurai help her overcome Engrish just for his little Kirby in the last one, then give up on her after the years? But Ness did get a new clip for PK Fire in Brawl. Perhaps Sakurai sent her a memo, "Rerecord PK F[smudge] voice clip."
But, yes. The first time I saw the Emissary video after Japan's release and heard Ness's voice clips, I facepalmed. I had the faintest hope that maybe the Melee voice was a new one made up when Ness was meant to be replaced by Lucas, and that maybe his Melee voice would be abandoned, he'd sound more like he did in SSB, and Lucas would have the voice I'd already heard by then... But it's fine. You get used to PK Frahs after a while.