There were other factors at play.
You have heard that american indians were killed by diseases from africa and europe?
In the first centuries of colonization—African diseases typically killed all the white settlers in the caribbean and the tropics.
Africans didn’t have problems with african diseases.
Can’t get an African disease without Africans.
Haitians murdered the whites, not diseases.
They weren’t negroes on Haiti before whites brought them.