Technically speaking, Israelites were not yet formed and the Tanakh wasn't given yet. However, I'm wondering if there is some kind of a principle, intuitively speaking, that would extend to them as technically, they were still descendants of Abraham, peace be upon him, as far as I know. So I'm asking as to what the status of these children is?
Sotah 12a implies that any baby born in Egypt got a ticket to Olam Haba:
A Sage teaches: Amram, the father of Moses, was the great man of his generation. Once he saw that the wicked Pharaoh said: “Every son that is born you shall cast into the river, and every daughter you shall save alive” (Exodus 1:22), he said: We are laboring for nothing by bringing children into the world to be killed. Therefore, he arose and divorced his wife. All others who saw this followed his example and arose and divorced their wives.
His daughter, Miriam, said to him: Father, your decree is more harsh for the Jewish people than that of Pharaoh, as Pharaoh decreed only with regard to the males, but you decreed both on the males and on the females. And now no children will be born. Additionally, Pharaoh decreed to kill them only in this world, but you decreed in this world and in the World-to-Come, as those not born will not enter the World-to-Come.