Chapter 11 isn't "bankruptcy" the way the uneducated understand it. It's simply a petition to the courts to allow a company time and breathing room to reorganize its debt. Far too often creditors want to swoop in, sell off the assets for pennies on the dollar and get themselves paid. Ironically, all that debt IS repaid, the people working for the company get to keep their jobs, and the company can continue to pay taxes. Only poorly educated simpletons fail to understand this.
Chapter 7 is a completely different animal. It involves the dissolution of all company assets to repay creditors, preferred stock owners, and if anything is left over, the common stock holders.
None of the companies in question declared Chapter 7.
But very intelligent, savvy, and smart executives know to use the laws Congress set up to perpetuate their companies and continue to employ people and generate revenue.