If you mutually agreed to forever waive your rights to spousal support as part of your divorce judgment, it terminated the court's ability to order spousal support. In this case, the court won't be able to grant your ex-husband request for spousal support if he files a Request for Order.
If the spousal support waiver terminated the Court's jurisdiction to award or modify spousal support, then no, it cannot be awarded by the Court later. If the Court's jurisdiction is terminated, it means the California court does not have the authority or ability to make orders regarding spousal support.
Disclaimer: This answer does not constitute legal advice, and should not be relied on. Each state has different laws, and each situation is fact specific. Without an in depth consultation and analysis of all relevant facts and evidence, it is impossible to fully evaluate a legal problem. This answer is not intended to, and does not, create an attorney-client relationship.
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