Contracts have been tossed by the courts for management as well. The difference is that, to a fault, contract are typically honored up to the point they're abrogated.
Someone who has earned severance, be it management or labor, prior to a date of abrogation, still is due what the terms of their contract say they're due. The only exception I can think of here have been retiree health benefits and traditional pensions. I've yet to hear of someone losing their past date 401K contributions in bankruptcy.
I think Parker is worthless, and so are many of the folks brought over from US, but this is the management your unions demanded.