Pls see the additional information I posted: I found a link that identifies reinstatement.
"Wrongful termination claims must usually be investigated by a government agency first before a private lawsuit may be filed. " NOT TRUE.
The source you got that information from is simply wrong. The government authorities, be they the DFEH or the EEOC will not investigate claims of wrongful termination in violation of public policy. That tort is beyond the jurisdiction of those agencies. They only have jurisdiction to investigate claims of violation of certain statutes over which they have been tasked with enforcing. That would be FEHA or Title VII/ADA/ADEA respectively. The tort of wrongful termination in violation of public policy has not government oversight agency that can or will investigate the claim prior to filing of a lawsuit with that cause of action.
That said, there are many cases where a violation of one of the statutes will also constitute a wrongful termination in violation of public policy, and if so, you can file an administrative complaint based on the violation of the specific statute, but not the separate claim of wrongful termination.
Be careful getting advice from the web. You have no idea about the competence level of the people writing those articles.