In general:
any optional form of payment is "locked in" at its commencement date, such that no one is entitled to change it later.
any J&S option will pay X to the retiree and some portion of X to his/her surviving spouse. The identity of such spouse is "locked in" at commencement date. Divorce and/or remarriage is irrelevant.
Very likely, a QDRO is also irrelevant, primarily because most plans don't allow changing a J&S election after commencement, so a QDRO cannot force a plan to do something that is disallowed by the plan.
However, some variations might exist (especially if the plan has a governmental sponsor), @Bill Presson's advice is essential.