Any flight changes will be updated automatically on the Trip Plans mobile app and URL shareable itinerary, if the changed flight is within 24 hours and as long as you opt-in for any changes to be updated.
If the changed flight is departing outside of the 24-hour window, the update will occur on the Trip Plans mobile app and the URL shareable itinerary every several days.
Please note: For the most up to date information, please check with the airline.