Japan officially annexed Okinawa in 1872. What do you mean with "rightful claim"? Did the USA have a rightful claim over what is USA today?

Japan forced Okinawa to join Japan. That's it. It did not need to ask for any "rightful claim".

I think in discussions about territorial dispute the importance of the status quo is often forgotten. It does not matter who historically owned which place. It matters who is owning it now, and who is trying to distort the status quo.

Of course, if local people are being oppressed, they might rightfully demand independence.

Edit: 1872, not 1972.