I'm of two minds on this. The protection of religious liberties in the workplace is from federal and state laws. Corporations have been ruled "people" with respect to the first amendment's speech protections. A state or federal law compelling corporate speech (by allowing an executive of a corporation to contradict the corporations chosen speech, within the corporation, not pertaining to protected speech outside of the corporation) seems to be preempted by the constitution here (as interpreted by the Supreme court).