Legal Question in Business Law in California

This is all governed by private contract in the USA, with limited exceptions that require large businesses with many employees to give some prior notice of large-scale layoffs or plant closings.

Not unless your company policies say so, however, nothing stops people from making claims and filing suit for whatever they deem up. You should set aside funds to have an attorney review or set up your polices, to prevent such problems, to the extent you can. If serious about doing so, feel free to contact me.