True, but they aren’t allowing recently admitted permanent residents, asylees, and refugees, all of whom have federal protections against immigration status discrimination in employment.

Some places like NYC offer legal protections in this area to all categories of immigration status, of course within what applicable federal and state law requires and allows. Federal law allows preferring citizens over equally equalities noncitizens, requiring employment authorization to already exist, and complying with any specific legal requirements for restricting certain jobs to citizens. NYC law respects all of this. But overall NYC is totally allowed to, and does, add protections beyond federal law.