Apparantly those who ship by air did not have any qualms about shipping with UAL, NWA DAL etc. when they were in bankruptcy.
Ch 11, generally allows a company to vastly bolster its financial in the short run, since they can obtain DIP financing and dont have to pay debt service, pre-petition obligations or union wages. I know of no major US coprporation that went into CH 11 and ceased operations within a year, some eventually do but much later.
The real worry would be that YRCW liquidates on Dec 7 if the exchange fails, but if shippers cared about that they would not be shipping now.