The filings aren't late, they are considered delinquent. From what I understand, the SEC has likely been sending letters asking for the delinquent filings for years.
Although filing the delinquent financial reports would be an act of good faith, GTGP still would need to go through the process of requalifying under SEC Rule 15c2-11 and FINRA Rule 6432 in order to be quoted again. This process is overseen by FINRA, not the SEC.
Keep in mind, that 10-K annual reports have to be audited by an SEC-qualified auditor. If GTGP has not had such audits, it would be very costly and time consuming to do them retrospectively.