Would be interesting to find out if ICAO can find a solution for countries not publishing reports.
One option might be to give interested parties an opportunity to file an official report (in their own language and english) at ICAO if the lead country does not abide by the rules (say for example after 3 or 5 years, which should give the lead country enough time). That official report could then be used by ICAO and the global aerospace community as the default report for that specific case.