Oh, it'll be investigated alright. Thanks to the CLEAN BREAK with the despotic past facilitated by the United States military and it's allies, it ain't gonna be like Russia or other places were politicos and elites motivated to bury their sordid history remain in power.
The Iraqis are and will be very interested in thoroughly examining their own recent history. Advocating and advancing such investigations will be an important means for many in the new crop of Iraqi politicians and intelligentsia to gain legitimacy or prestige. There will be tremendous energy devoted to sorting this all out.
"Certain people" should be, and doubtless are, very afraid of a new Iraq full of free and inquisitive citizens.