They've already successfully ratcheted the Overton window. We've gone from "there are a couple written reports of an African slave visiting Japan with jesuits, we've heard tales but we can't say if they're factual for sure" to "Yasuke was ONLY a retainer to Nobunaga!" In the future we'll all agree that "No of course Yasuke Muddafugga Mifune wasn't technically a samurai, but he was an important warrior who assisted the samurai in unifying the country, freed all their African slaves, and bred with many Japanese ladies which is why there are Japanese with curly hair today."