I am pretty sure Ridley and Dark Samus have enough Japanese appeal too. If even Banjo was not totally unknown to them, no way that character from an actual Japanese Nintendo franchise would go under the radar for them either. In all honestly, no single character in Smash so far is 100% unknown to Japan. That would change if someone like, say, Doomguy, Heavy or Master Chief were added to Smash, who are what Ness was to the West before Smash 64.

"Nobody wanted dark samus"

Says you. Dark Samus is the third greatest character in the entire Metroid series.