I have read that after the slaves were set free some of the petitioned to stay in slavery because they weren’t able to support and feed themselves. They needed the security of being taken care of.
In the early colonies - yes, up north in Massachusetts - colonists were not allowed to free their slaves without posting a bond. The towns didn’t want to take on the expense of caring for the freed slaves. So instead of posting bond the owner would free the slaves but kept them in the home and called them servants.
If you do any kind of genealogy and look at the old census records you’ll see that many families had non-family members living with them. They worked in the house or out on the farm in return for room and board.
I am aware of what you posted...