I don't know what is normally done, but this is what happened with us!
The day of the Superbowl this year, we had a flight. I had tried to tell DH that we should change it, as it became more apparent that he might be in severe emotional pain being on our connecting flight (out of Newark no less!) that left before it started and landed in Seattle after it would finish. DS and I were on miles and hubby was booked for cash.
Got to MCO nice and early as we like to do. The area started filling up. DH was getting really sad about flying. And then they announced it. They needed volunteers.
The lines to the desk were already really long. DH made the decision to go straight to the desk, bypassing (cutting) the lines. The people in the lines were already waiting there, they weren't getting into line based on the bump option, and since the employees did not turn him away as they would have done if he had just gotten impatient about a normal thing to go to the desk for, it turned out OK. (and even though I am vehemently against "cutting", I think in this case it actually HELPED the people already in line, and again, since he wasn't turned away, I think it was OK and I would recommend it to others in such a circumstance)
They needed 9 volunteers, and we were 3. So we got on the list. At that time they were offering $300 vouchers and a flight out, etc.
Once it was all taken care of, they were offering $400 vouchers; they weren't able to do 3 $400 vouchers, so they gave us 4 $300 vouchers, which kind of works out better given the prices we generally travel under. This was a VERY busy travel time (the next day was worse), and getting us out that day wasn't possible. Nor is it what we wanted, anyway.
They also gave us food vouchers for the airport and/or the hotel they sent us to. Turned out to be only $7 per person per meal, which doesn't get you very far, but we dealt with it. In our case, DS and I didn't have much of an appetite anyway, so it worked.
They put us up at the Doubletree. Tried for the Hyatt in MCO but it was full. Oh well.
And while travel out the next day was difficult, and involved a few extra changes to the flights, it worked out. For some reason, United found it impossible to keep our reservations connected, but even that worked out. DH was upgraded to Business class for one of our flights, and no one had a problem with me using his ticket so that I could have some ME time and DH could have some "play videogames with DS time".
Oh, and DS and DH got to watch the Superbowl on the BIG TV in the Doubletree lobby, while I got a bonus day at Epcot. Win win! And, for DH's team, win.
Worked out well for us!