While this is true, most people are not aware of the use of those terms and if I called them "originies" or "originals" I would probably be corrected for typos and if I called them"black fellas" I would be accused of racism. Either way, my point would be lost. Calling them "native" doesn't help much either as the definition of that is anyone born on the land they live on and that includes non originals.
Since we're not talking in legal terms then, in law, the generally accepted meaning of a word and the belief in that meaning is what is taken as the meaning.