The RA2-5 you see in the publication was as resulting from this process, not as selection criteria themselves.
Very interesting, yes, quota probably wasn't the best choice of words. I was speculating based on the data showing that from RA 2 to RA 5 the entry requirements/scores continue to decrease amongst all criteria (interview score + GPA/OP/ATAR). Therefore I assumed maybe that as you increase in rurality, so does the boost you get to your entry scores. Therefore in order to do that in the first place they would have to have a system in place to differentiate a candidate who is RA 2 from RA 5 consistently which you wouldn't be able to do from Q1-Q4 but you would with schooling.
Or I am completely wrong as you pointed out and its merely that someone who emphasizes rural in their application is more likely to be RA 4-5 in the first place and gets a higher boost.