American Samoa is governed under hereditary rule in a manner completely incompatible with American law and the Constitution. If American Samoa wants to gain all the rights and priviliges of full citizenship, they can very easily give up their hereditary aristocracy. You can't eat your cake and have it too.
I do favor an easier path for full citizenship for AS nationals who move to the US proper.
Precisely why the government of American Samoa filed a brief opposing certiorari in this case (and, I imagine, why Gorsuch and Sotomayor didn’t dissent from the denial of certiorari even after calling for the Insular Cases to be overturned in Vaello-Madero). Maybe some other case will come out of Puerto Rico or Guam and the court can fashion a solution that extends the Constitution to all the territories but AS.