yeah, it's unlikely. However there are now two "boots" of this kind reported, both have mask roms and the eproms might be the ones needed for the localization... maybe SNK had these games manufactured mainly in Korea itself and shipped only the mask roms there? It does say "Made in Korea" on the label - other localized releases do so too (there are exeptions e.g. "Fighter's Swords" [SamSho III], which had "Made in Japan" on the label), but it might have been a 1996 thing... or the only release they went this route with... SNK is known for their inconsistencies, so I wouldn't put it past them...
Maybe we can get more people with Korean Waku Waku 7 copies to chime in?