aunt and uncle got to become servants?

They were the grandparents, not the aunt and uncle. They weren't actually slaves, it was a cover story while the main guy was there. When he wasn't around they were just chilling in their new bodies. That's why at the end the girl says "Grandma" - as far as she's concerned he has driven off with her Granny, but the main guy just thinks he's rescuing a poor black servant who has been mentally altered against her will. That's why the "black servant" goes mental at him in the car, she's really the granny.

They only wear maid and worker uniforms to keep up appearances. Otherwise, why would you have a young black couple living with a middle aged white couple in the same house?

In terms of lifestyle, they seem to do typical Grandma and Grandad things... They were probably also putting on a show for Chris, in ordrr to entrap him...

P.S. I didn't see the previous comment as I didn't refresh the page... 😁