What could possibly define "heritage", other than racial origin? Racial origin would be the only thing you could subsatantiate. Cultural "heritage" is too nebulous to stand up to any sort of test; anyone can adopt cultural behavior. So, if Kennewick Man and the Europeans of today share a common racial origin, that would be all that would be possible, or necessary, to provide proof of common "heritage", if the matter were in dispute.
The Government entitlements which Indians receive are entirely race-based; they have nothing to do with economic status.
Actually, I'm curious - what does one have to do to prove one is "Indian" enough to receive the Federally run health care?
The bottom line is, you have absolutely ZERO evidence that "Kennewick Man" is anything but racially of Asian origin. That is the whole point, and there is nothing - NOTHING - about Kennewick Man that will end any Treaties, agreements, or any other arrangement that our Government has with the various tribes.
So chew on THAt for a while, and come back and talk to me when you can accept that fact :0)