Sounds to me like the part about calling Irish people Mulatto in order to keep them enslaved, which I never heard of before, is an attempt on someone's part to deny that the Mulatto(s) they found in their family tree were actually part African....
Otherwise, I don't doubt that a lot of Irish were sent here to forced labor..Those were people who had been in prisons in Ireland, weren't they?
But then there were those who came here on their own and worked to pay off their passage..They were bound to their *employers* for various periods of time I believe..