It seems like either a typical class action suit. The city's negligence/unenforcement led to higher rents in that neighborhood. Or could be even easier to show

It seems like either a typical class action suit. The city's negligence/unenforcement led to higher rents in that neighborhood. Or could be even easier to show that the lack of said units led to displacement for actual families. I'm not saying it's easy peasy but if affordable unit advocates believe they are important then logically enforcing the regulations they fought for shouldn't be just shrugged off, at least as a signal to cities and developers.