After receiving a notice of bankruptcy from a customer or other source, is it permissible to simply stop reporting their loan to the bureaus? I can't find anything that would specifically prohibit a creditor from doing so. This is being considered for ease in tracking the bankruptcy statuses and credit reporting accurately due to limited resources.

Sounds like a potential fair lending violation if you report other past due loans and not report for people in bankruptcy. It likely violates your credit bureau contract. You do not get to pick and choose who you report on in any given product line.