She can't and won't say anything about the investigation content. best we can hope for is some sort of feel for momentum or scale of the crimes.
Remember Alias? The ABC show, Jennifer Garner and the pink wig and stuff?
Her character, Sydney, thinks that taking down her double-timing covert organization she got sucked into working for is something she can do by Christmas with the help of the authorities. She even draws a small org chart to indicate the target.
And then, her handsome handler (love interest yo) shows her his own board. There are ten times as many players in the game as Sydney imagined when she became a double agent on behalf of the government. That show was just getting started.
This is that. Donald Trump has been protected, enabled, and allowed to run a cruel fiefdom for decades. Donald Trump has raped, stolen, and mistreated residents and gotten away with it. He has pasties, loyal and knowing servants, and now has the support of millions in addition to the grudging support of the party of government (if only because they rightly fear their own illegitimacy and destruction for letting this creep take it over). One interview isn't going to knock this president out. One hearing might not do it. It can happen and I increasingly suspect it will: one way or another, the Trump regime stands a good chance of destroying itself. Just not as quickly as we want it to.