
Palestinians are primarily descended from local pre-roman Jewish, Samaritan, Canaanite, and Nabatean populations who were culturally Christianized and then Arabized. The attempts to remove the indigeneity of Palestinians based on cultural shifts is like trying to say the Irish have no right to the land because they became Christian and speak English.
Also, it should be noted that when Israel was razing depopulated Palestinian villages in the 1950s, several historic Palestinian Jewish synagogues within those villages were also destroyed. In their effort to erase the history of Palestinian Muslims and Christians from the landscape, the state was also erasing the history of Palestinian Jews.
Also settler colonialism can often happen where someone’s ancestors came from. It’s about the dynamic of displacing locals, not about where someone’s ancestors originated. Liberia and Sierra Leone were both founded as settler colonies by people whose ancestors came from the region.