No, the point was NOT that populations shift and move, the point was "systematic killing", remember?
If you want to start from the same year to compare apples to apples:
Then (1939): 1 million Arab "Palestinians". Now: 15 million Arab "Palestinians".
Then (1939 pre-Holocaust): 16.5 million Jews. Now: 15.8 million Jews.
There should be 30 million Jews in the world, at least. And that would be if the Jewish population only doubled since 1939. If the Jewish population had exploded (and was counted) the way the Arab "Palestinians" did, there would be 248 million Jews in the world.
That is what systematic killing looks like.