The US should be giving land back to native Americans and should at the very least compensate the native Americas. Moreover, native Americans are part of the US as well. Thus, for your analogy to work, the Malvinas has to be part of Argentina.
In the US, the contemporary residents (read: white people) decided what to do regarding native american claims. In the falklands, the contemporary residents (read: the islanders who want nothing to do with argentina) have the same right. The analogy works perfectly.