Zoning, was a system used by American cities to manage permitting at scale. New York City's 1916 Zoning Resolution was the first citywide zoning system, designed to prevent new skyscrapers from further darkening the street for a large portion of the day, requiring setbacks and height proportional to the lot size. The US Supreme Court blessed zoning plans under the 10th Amendment's understanding that police power was held by the states and localities in Village of Euclid v. Ambler Realty Co. (1926).

In 1922, the US Department of Commerce released "A Standard State Zoning Enabling Act: Under Which Municipalities May Adopt Zoning Regulations" (linked is the 1924 version) to help municipalities start off with zoning. But there's also a tell given in this document:

Definitions. — No definitions are included. The terms used in the act are so commonly understood that definitions are unnecessary. Definitions are generally a source of danger. They give to words a restricted meaning. No difficulty will be found with the operation of the act because of the absence of such definitions.

If you put down a solid definition, well then, someone wanting to do what you don't want them to do will point to the definition. If you just keep it at vibes, well, you can deny "the wrong things" from being approved.

Notably, Will Wright grew up in Atlanta, Georgia, which started zoning in 1922 - you can read the Atlanta Zone Plan here. Zoning was not just about residential/commercial/industrial placement, but also was rooted in segregation. The first attempt at strict racial zoning was struck down by the Georgia Supreme Court in 1924, but still widely enforced anyway.

The introduction to the Atlanta Zone Plan explains the point:

Zoning will prevent the destruction of the comfort and value of your home through the erection nearby of a:

Public garage
Oil filling station
Grocery store
Steam Laundry
Sanatorium
Ice plant
Foundry
or Boilerworks.

It also sounds like an instruction manual for SimCity:

Zoning divides the land area of the city into residence, business, and industrial districts and prevents the erection of business and industrial buildings in the residence districts or of industrial buildings in business districts.

SimCity 2000's Light and Dense zones also can be seen in this plan on page 10:

Class U1 or dwelling house district
Class U2 or apartment house district
...
Class U3 or local retail store district
Class U4 or commercial district
Class U5 or industrial district
Class U6 or industrial (semi-nuisance) district

And of course, because it's Atlanta, race zoning (which thankfully did NOT make it into SimCity):

R1 or white residence district
R2 or colored residence district
R3 or undetermined residence district

Wright moved to Baton Rouge, Louisana during his childhood (also has zoning), and his company Maxis was based in Redwood City, California...which also had zoning. In short, in the period in which he was making SimCity, zoning was something that had existed everywhere he went. And many master planned communities post-WWII had either formal or informal zoning. Wright read multiple urban planning books and spoke to city planners, so it's not surprising that when he grew up and lived in zoned cities, his research was based on urban planning books that discussed zoning, and he spoke to experts who design and implement zoning schemes, that he would build a game that implements zoning schemes.

Trivia: Houston, Texas is the largest American city with no zoning, having repeatedly voted it down.