Originally Posted by
drsmithy
Not without a notification and option for refund they're not.
Jumping off the flight halfway to pay less aside, a passenger might be planning on using that layover in B specifically to meet with family, conduct business, etc. Changing the interim stop represents a quite significant change in the agreement - infinitely more than a passenger not flying all segments.
That's not my experience. Often (OK, once a year or so) an airline has changed a flight AAA-BBB-CCC to some other routing.