It's a fairly amazing development that other states (and cities) should pay close attention to. Localizing zoning is a fine idea when the concerns are truly local, but when it comes to housing costs, the effects are much more regional. Left to business as usual, zoning changes at a pace that does not accommodate demand. Worse yet, when zoning changes it's often only can occur via a backroom deal, which privileges developers with access, ability, and willingness to manipulate the systems.
When a developer spends 1 year planning a project, prices go up. Part of the reason is by necessity, as more time is spent and any expenses must be financed longer. But another reason they go up is that the market becomes more exclusive. Not only must the developer charge higher rates, but they can charge even more. In that type of market, a developer makes profits via high margins, not high volume.
Taking the approach Oregon has, opening up change en masse, creates opportunities where development will follow a model more like that found outside cities, where prices are lower. Prices will still be higher, the land value is still higher, and there's some other requirements to meet, but the gap will be smaller. Unlike the suburban building though, this new building will be higher density, providing more people with access to the local job market and other services of the developed city.
Chicago, and/or Illinois should follow this example. While housing prices have not spiked here in the same way as they have on the west coast (or northeast), they have been still been rising in comparison to household income in a way that is making housing less affordable, and the city more exclusive.