That’s how I read this article. The two principals are the DOJ and the FBI. They have to sign nondisclosure agreements in order to read it. Which doesn’t necessarily mean someone won’t leak the info to some of the players involved.
It will get leaked, but I doubt there is much good in it for the FBI/DOJ. That’s why the NYT did the story today to try & cover the deep state concerning the physical asset they planted with Trump. Whatever the IG report says....it’s another nail in the coffin.