Suppose we finally reach a point where we don't treat races differently in any sense that matters. There's no more even unconscious discrimination. The structural barriers that in most contexts favor whites more than other races and some non-whites over other non-whites are gone, even those instances when no one intends to do harm. There are no more people who have negative attitudes toward people because of race. (So far this is all the same as #9.) Suppose further we have abandoned the use of racial terms, not just terms like 'race' but even terms like 'black', 'white', 'Asian', and so on.
If you don't think races exist now, you'll obviously not think they exist in such a circumstance. But if you think races exist now, will they still exist under such circumstances?