That's correct. The people of Canaan weren't eating pork at the time that they were polytheists. The business about Noah and Ham (is this porky name a bizarre coincidence?) was needed to disassociate the true identity of the Canaanites from the peoples minds with their now (sardonically) superior new identity of having origins of being the descendants of slaves of the Egyptians. Abraham's god, whose correct name he didn't know, told him that his descendants would first have to be slaves for (yes - both) 4 generations and 400 years in Egypt. Who was left around to gainsay this by the time of the Babylonian Exile? There is no evidence for such slaves in Egypt, unless one wants to consider such as the Shasu nomads from parts such as Moab. And that much of the Egyptian based narrative is also a paean to the Hyksos period.In other words, we should question whether we are being sold the story by the Jews (don't eat pork) - or a story told by the Egyptian elite about 2 opposing groups of people who don't eat pork - since all kinds of animal bones turned up in Finkelstein's excavations - except pigs? Finkelstein also doesn't find a sudden appearance of new peoples hence the reason why Genesis refers to "Canaanites"?
BTW, the Egyptians were also categorized as being of the descent of Canaan, this being convenient within the contemporaneous geopolitical milieu of the Persians, who would soon come to control Egypt.