The only potential reason is that once the bankruptcy filing reaches the courthouse, the union loses any control. In bankruptcy, contrary to what Bob posted in the other thread, there are two stages to contract abrogation. The first is temporary and for all intents and purposes automatically granted - temporary changes to the contract as desired by the company. Negotiations can, and usually do continue. However, if no agreement is reached the company can ask the judge for permission to abrogate the contract (throw it out), replaced by whatever it wants until an amendable date. At that point negotiations are over unless the company wishes to continue negotiating - you or the union likely have absolutely no say in what's in the contract as long as the judge finds what the company wants to be necessary. I think it was either the UA or NW bankruptcy where a group's contract was abrogated. They threatened to strike but a district court ruled they couldn't. I don't know if that ruling was appealed, but the end result was that there wasn't a strike. In the US bankruptcy, the IAM contract was abrogated but the company kept negotiating to get a ratified agreement but that was before the court ruling in the UA or NW case and I think US was afraid of a strike shutting the doors and the company liquidating.
Jim