Originally Posted by
NoValueAviator
Yes, you are correct. They will simply remove you. The scenario imagined where someone lists for an earlier flight, no-shows, then drops in front of the D2s for a later flight with their earlier check-in time is in the imagination of the people complaining about it. The only way this might happen is if you run up to the gate before the agents leave but after the flight closes and tell a good story.
Actually, you can get any gate agent to do it, not just the one working the flight. There are legitimate reasons to have a gate agent change your itinerary but I could see how someone could abuse it too.