IG report = slow roll
I think it depends. Rosenstein wanted to assign it to a DOJ IG, in which case a new startup investigation would be a two year slow-roll. Expanding Horowitz' authority, when he's got several hundred people who already know much of the ground to be explored, might be a good thing.
Devil, details.
IG as I understand it can only address those still working for the DoJ/FBI?