I hate that people's instinct is to play 4D chess with the intent of some random Wiki editor instead of even glancing at the data contained in the references. Here are some aged references for your discerning palate:

Density Zoning and Class Segregation in U.S. Metropolitan Areas (2010) https://doi.org/10.1111/j.1540-6237.2010.00724.x

Distributive politics, ward representation, and the spread of zoning (1993) https://link.springer.com/article/10.1007/BF01047991

Urban Land Developers and the Origins of Zoning Laws: The Case of Berkeley (1986) https://escholarship.org/uc/item/26b8d8zh

Fifty Years of Zoning (1966) https://www.jstor.org/stable/25723800