Legal Question in Business Law in California

Yes.

......and the reason is that, absent a written contract (such as a union collective-bargaining agreement or an individual written contract such as a baseball player might have), there is no "right" to employment, and, for example, an employee can be dismissed effective at once. So, consequently, an employer has a right to withdraw an offer to employ you. To be sure, an employer cannot discharge an employee for a bad reason (such as, the employee reported employer misconduct such as unlawful discrimination), but it's generally within the employer's rights to terminate an employee for a good reason, or no reason at all.