To receive a refund, the traveller will need to cancel / change the flight. If they stay on the same flight (just changed their mind) there is no refund. This is the same for E+ access fees and upgrades to a premium cabin. Refunded only if the particular flight is cancelled (or you change to a different flight).

Generally speaking front 1/3 is E+, the middle 1/3 is preferred (and free at check in) and the back 1/3 has no fee. Many flights are filling up. Note Basic Economy flyers don't get early seat assignments.