The holocaust of the Jews was a heinous crime against God and humanity. For those who don’t believe in hell, I ask you where do you think the soul of Hitler and his mass murderers will be spending eternity?
That being said, the Holocaust doesn’t necessarily mean that the Jews are still God’s chosen people. The Khmer Rouge government in Cambodia exterminated half that country’s population in the 1970s. That doesn’t make the Cambodians God’s chosen people in and of itself. The Armenians were massacred by the millions by the Turks not many decades ago. That doesn’t of itself make the Armenians God’s chosen people, yet God allowed these exterminations of non-Jews to take place.
According to Christian theology based on the New Testament, however, the Jewish people ARE still especially beloved of God
"for the sake of the Patriarchs," as scripture puts it. So yes, the continued existence of the Jewish people is in their case a sign of God’s loving providential care for them, especially considering what they have suffered over the centuries and the horror that was inflicted on them in Europe in the mid 20th century by the Nazis.