Typically I'd agree, but the SNK fighters are pretty intertwined. KoF itself was designed to bridge existing series together.
I mean, look who's on the cover of the latest entry.
It's all much more connected than most series are. And frankly, I suspect Nakoruru's chances are greater when under the SNK fighter umbrella than otherwise. Because new entry or not, I don't think Samurai Shodown is the series Sakurai would prioritize above the others.
So if he really broke it down on a per series basis, I think Nakoruru's case becomes significantly weaker. This isn't a 1:1 obv, but consider Morrigan's case if Sakurai, seeking another character, assessed her based only on Darkstalkers.
It's true that among solely the Samurai Shodown cast, she stands at different odds, but that's forgoing the bigger series to focus on a smaller one. So even if narrowing the pool makes her likelier, the act of narrowing it to that extent in the first place brings the unlikeliness back.