Actually I believe he said an additional 25 million would have to be killed after the race wars were over and they had won and after the country had been divided into three different parts controlled by foreign governments.
How many he expected to be killed in the race wars and the wars against occupation by foreign govts. was never spelled out as far as I know.
In any event, he envisioned such a scenario for those opposed to socialism/communism. And he is one of Obi's best friends...