Will airlines allow you to go standby this way

My wife has a flight from:

Mexico to Detroit

Detroit to JFK,

Then JFK to Boston.
Anyone know if they ever let people go standby, and just fly straight to Boston from Detroit, and skip the JFK flight. She’d obviously be asking when she got to Detroit, and not beforehand.
ps- it’s on Delta, and she has Platinum status (not sure if that helps or not)

I think if she has checked baggage, they may not let her skip the JFK flight, if the baggage is already on it. They really want you to be on the same flight as your checked bags.

Should be able to without a fee, as a platinum status holder:

https://www.delta.com/us/en/change-cancel/same-day-flight-change

She’ll have to clear customs in Detroit so would collect and then recheck her luggage there.

No luggage. Just carry on bag.

With status, I’ve had some luck doing this; however, you will end up with a middle seat beside the lav! But don’t bother trying at the airport. Call the platinum service number and have them change it- it helps to give them the exact flight or two that you want to get put on to Boston. (i.e. Make them tell you no! rather than yes that would work.)

I’ve had the best luck when there is some whether or delayed flights at one of the locations (ideally JFK in this case) as they prefer decreasing their passenger loads at such an airport.