Non-Debtor ops continue BAU.
As long as the business is running smoothly and no additional capital is required, everything is fine. If capital is required, then the Court has to approve. In LEHMQ, for example, Aurora Bank FSB and Woodlands Commercial Bank are non-Debtor subs. LEHMQ had to obtain approval to provide additional capital. If not approved, the banks would have failed.
Creditors cannot go after a non-Debtor sub. If conditions warrant, they would also file for bankrupcty.
If you aren't an Enterprising Investor, become one—you'll love making money like Benjamin Graham.