Originally Posted by
sethb
They'll modify; if you're flying a shorter distance, they can request ORC. (That is, they can't grant it, but they can put in the record that they offered it. I did that when taking a bump from DFW-SLC (-JFK) and getting re-routed DFW-LGA. I called in after I arrived and got ORC because it was in the record.)
ORC doesn't need to be asked for at gate. DL by policy will grant it if asked.