Perhaps they dont want it release 1) because it is inconclusive and 2) because the nation of Turkey has in the past not been very interested in having treasure hunters or even legit archeologists running around in that area where there are still hostilities between the Turks and Kurd rebels.
Also, Turkey is polulated by moslems who know that they are descendants of Noah. They dont need scientific truth of that. Why do us Westerners seem to feel they need to be able to point to the ark in order to believe?
Perhaps they don't NEED it 'to believe', but WANT it to PRESERVE it.