The SEC only cared about ATP's delinquent Financials and the company's expected filing obligations even in bankruptcy.
ATP could not or would not file Financials which is the primary obligation for SEC registered companies.
Excerpt from the Admin Proceeding: (hilites mine)
ATP Oil & Gas Corp. (“ATPAQ”) (CIK No. 1123647) is a Texas corporation located in Houston, Texas with a class of securities registered with the Commission pursuant to Exchange Act Section 12(g). ATPAQ is delinquent in its periodic filings with the Commission, having not filed any periodic reports since it filed a Form 10-Q for the period ended March 31,2012, which reported a net loss of $131,521,000 for the prior three months. On August 17, 2012, ATPAQ filed a Chapter 11 petition in the U.S. Bankruptcy Court for the Southern District of Texas, which was still pending as of August 18, 2014.