Religion & Law

From the Compendium of the Social Doctrine of the Church:

The Magisterium recognizes the fundamental role played by labour unions, whose existence is connected with the right to form associations or unions to defend the vital interests of workers employed in the various professions. . . . Such organizations, while pursuing their specific purpose with regard to the common good, are a positive influence for social order and solidarity, and are therefore an indispensable element of social life.

It may very well be the case that public employees' unions have been too late to recognize that fiscal reality requires significant concessions on their part, but can a requirement that those unions give up the bulk of their collective bargaining rights be reconciled with Church teaching?  Or is Church teaching hopelessly outdated on this front?