Indeed, as mentioned in the comments, the lands of the remaining three tribes were promised to Abraham alone, and were not mentioned later in the promises specified to the children of Israel, and as Rashi writes (Deuteronomy 2:5) in the name of the Midrash Rabbah, that one of those lands was given to the children of Esau, and other two were given to the children of Ammon and Moav, who were the sons of Abraham’s nephew Lott.