Yeah, I did not have thought of this point of view. In my country, we see the world as 6 continents, not 7 as America is just one. Of course we do the difference between south and North America, but they are merely subcontinents (like India, It is located in the Indian subcontinent but it is in Asia). Therefore, all people that lived in the continent are "Natives americans", to the northern inuit to the southern mapuches and everything between them.
Writing this, I also notice that the meaning of America can be different too, as when I read "native American" for me the meaning is "american= Whole continent", but for other people it could mean "American= Person from the USA" (so natives tribes inside actual USA).
I find funny that different cultural points of view can change the perception of the actual state of the game!! For me they are 5 native americans civs in the game, but for others just 1! so of course some people will ask for more, as they are underrepresented!
PS: Just for sharing another curious difference, we also may use "Americas" in plural, but with 2 main meanings. To differentiate the latin American part of the anglosaxon one or, in history, when you called all the different kingdoms in the same geographical sphere of America.