There is no archaeological evidence of anything as drastic as total or even massive replacement of population at any time in the history of Canaan/Palestine, though it does seem that over the centuries before Herodotus ‘Palestine’ somehow took over from ‘Canaan’ as the most commonly used name.
Eric Cline – ‘1177’ – (2014, p. 95) – does think that Canaanite civilisation was destroyed in the 1100s, to be replaced eventually by Israelite and Philistine emergent states and cities, though these are strong remarks compared, say, to those of Amihai Mazar ‘Quest for the Historical Israel’ – (2007, comparing Mazar with Finkelstein, p. 96) – where Canaanism continues for some time and the Phoenicians represent a new aspect of Canaanism. Cline goes on to dispute (p.159) Lawrence Stager’s idea of a rather ferocious Philistine conquest of southern Canaan in favour of a picture marked by ‘lack of violence’. None of this comes remotely near to population replacement. Stager himself had in fact produced twenty years earlier in the Oxford History of the Biblical World p.94-7 the most succinct and persuasive argument I know against an ultra Joshua-based conquest and ethic cleansing account of Canaan as a whole.
There was never any massive ethnic cleansing of Canaan/Palestine in Biblical times except by Sargon after 721, the fall of Samaria – even that was not quite the horrible kind of thing we hear of in our own days – and on a smaller scale by Nebuchadnezzar after the fall of Jerusalem. I don’t really think that the Bible says something different. I do think it inconceivable that most people now in Palestine don’t have ancestors – and a fair number of them – among those who lived there in the first millennium BCE.
Of course the theological interpretation placed on the very ideas of Israel and Canaan by the Biblical authors is much more important than the underlying history and much more significant for the relationship of Judaism, Zionism and Christianity.