This is a critical point. Naturally nobody wants to be contractually locked to a bankrupt regional feeder, so that is a routine contract clause.

With everyone looking to unload regional capacity in general, (and mesa in particular) a Ch.11 filing would provide an easy out for DAL for sure, USA almost for sure, and probably UAL as well.

Loss of even one major codeshare combined with very low propsects for DIP financing would almost certainly cause a judge to shut them down if they file Ch.11.

For this reason I think JO will not intentionally attempt to use Ch.11 as a reorganization tool. He'll probably go kicking and screaming straight into Ch.7, following FBI raids on the Crystal Palace.