I sympathize with your position. The use of "slavery" in the urban plantation context takes great literary liberties. It's calling being "brainwashed" being "enslaved" and pointing out parallels with the plantation.

On the literal plantation, who's the best slave master but the one who gives all his slaves "freedom" yet they remain with him and do his bidding (and sometimes even take a whipping)? If a slave master did that (IIRC it wasn't unheard of), would it be wrong to call the "enslaved" freemen "slaves" still? It's an interesting question.