I found this interesting document on the webz, and I think it is about 15 yrs old. See the interesting part in red. Maybe the delay is the IAU Working Group technical review?
IMPACTS AND THE PUBLIC:
COMMUNICATING THE NATURE OF THE IMPACT HAZARD
NASA Ames Research Center
Moffett Field, CA 94035-1000 USA
Clark R. Chapman
Southwest Research Institute
1050 Walnut St.
Boulder, CO 80302 USA
Joule Physics Laboratory
University of Salford
Salford M5 4WT
Massachusetts Institute of Technology
Cambridge, MA 02139-4307 USA
4. ROLE OF THE IAU WORKING GROUP ON NEOS
In the absence of national or intergovernmental agencies to deal with the NEO impact issues, the International Astronomical Union (IAU) has assumed some of the responsibility by default. The IAU formed a Working Group on NEOs in the early 1990s to advise on coordination of NEO activities worldwide, on reporting of NEO hazards, and on research relevant to NEOs. In the wake of the media interest and widespread public confusion associated with asteroid 1997 XF11 (to be discussed in more detail below), the IAU also assumed a limited responsibility for providing authoritative information to the media and public on possible NEO impacts.
When someone predicts a close approach to Earth by an asteroid, a subcommittee of the IAU Working Group can be convened (if so requested) to advise the IAU on the reliability of the prediction. The IAU Technical Review Committee of international specialists offers prompt, expert review of the scientific data, computations, and results on NEOs that might present a significant danger of an impact on Earth in the foreseeable future. The use of this review process is voluntary, and researchers worldwide remain free to publish whatever results they wish in whichever way they wish, at their own responsibility. In several cases the IAU has also seen fit to post a statement on its own website <http://web.mit.edu/r...eo/Public.html>discussing the reliability of impact predictions.
The initial purpose of the IAU Technical Review was to encourage scientists to check each other’s data and calculations before making public statements about possible future impacts. Such a review has been invoked half-a-dozen times. However, with the advent of automated systems to calculate orbits and generate impact probabilities, the need for such human intervention has largely evaporated. In practice, if the NEODys and JPL-Sentry systems agree on a prediction, it is considered confirmed, and the IAU has no direct role to play.
Communication with the international scientific community and with the interested public represents an important part of the Working Group efforts. One tool for public communication is the Torino Impact Scale described above, which was endorsed by the IAU. The IAU has also encouraged the use of several websites for improved communications. These include the NASA NEO Program Office <http://neo.jpl.nasa.gov>,the NASA impact hazard website <http://impact.arc.nasa.gov>, the UK NEO Information Centre <http://www.nearearthobjects.co.uk>, the Spaceguard Foundation and its on-line magazine Tumbling Stone <http://spaceguard.ias.rm.cnr.it/SGF/>, and two sites that post continuously updated orbital predictions: NEODys <http://newton.dm.unipi.it/cgi-bin/neodys/neoibo> and Sentry <http://neo.jpl.nasa.gov/risk/>.
The role of the IAU is limited: it deals only with the discovery of NEOs, not with mitigation, and it has limited ability to respond rapidly to new discoveries. From the IAU perspective, it remains the responsibility of the individual science teams to decide whether to release information to the public and the press on NEO discoveries or orbital calculations.