I don't think so. Kennwick man can't be of ainu descent because kennewick man came first.
Maybe what you meant was that both kennewick man and the ainu are descended from the same ancient race.
"Maybe what you meant was that both kennewick man and the ainu are descended from the same ancient race." No, I meant to say Ainu because that's what James C, Chatters, PhD (He did the Kennewick Man work) said in his book, Ancient Encounters.
Now, having said that, I do agree with you about a more ancient race and I would prefer the Jomon instead of the Ainu.
Kennewick Man