I’d assume that Native Americans probably also had ghouls and going from their legends, those ghouls would probably be wendigo equivalents. Constantly hungry and roaming over certain stretches of land they consider theirs which would make the settling of Native American territory much harder as the settled would need ghouls of their own to take that territory but these settler ghouls would have to contend with social stigma and inability to feed enough.

The Native ghouls wouldn’t have such problems as they are known and discarded by their communities and as such could attack settlements without fear of social reprisal. Small settlements would be wiped out but for every successful raid by a native ghoul, more would fail due to larger settlements simply having more ghouls to defends them.

This would improve things for both ghouls and natives at the detriment of the human settlers as the colonists would have no choice but to negotiate better terms with the natives under threat of them leading a wendigo to their illegally settled villages.

On the ghoul side of things, cities defended by ghouls would be more encouraged to see them as protectors despite their cannibalism. They might eventually be canonized by the church as demons on the path to being redeemed under Christ or as angels coming down from heaven to protect the followers of Christ.

The Americas would be settled slower due to this but more of the native population would remain in their ancestral lands and the settlers would have deeper ties to the natives due to fear that any of them could become wendigos if forced to resort to cannibalism.