@Kenv
I would agree that the KC-46 award doesn't seem to add to the industrial base for tactical aircraft design, but a fair amount of what's going into the KC-46 is coming via Boeing Defense and certainly supports its continued existence. I also expect that, as with the C-135, there will be many variations/ modifications of the KC-46 over the years to come to provide for additional missions unrelated to AR.
All of which, whether you agree or not, has little to do with the choice for T-X.
Too bad so many candidates just don't have that dashing beauty of the T-38.