I can just imagine holding some weird auction that 95% of people are unfamiliar with in a crowded boarding area full of annoyed passengers :-) That will end well.
I've been in boarding areas where this happened. The offer started at $400 and ended up at $1,000 by the time they got enough people to accept. No one was outraged (and I was quite happy to get 2x$1,000 in vouchers in exchange for a minor inconvenience).
A reverse action is offering $2K. More people than we need. OK, how about $1500? Still too many. $1000? OK, right number.
"Wait! You offered us $2K and now you're only going to give us $1K. Lying POSs."
At least that's what I think people are referring to as a reverse auction in this context. I'm not sure if that's a totally accurate description or not.