Mueller trying to control the narrative on why he will not testify publicly. Maybe Nadler threatened him with a subpoena. Or Mueller is going political and will say that he didnt make a decision on obstruction charges because DOJ rules say you cant indict a sitting President.
It will be interesting to see if he touches the subject of declassification by the AG on the origins of Trump collusion. Will he side with Brennan, Clapper, and Comey and warn against revealing this material?
The IG report will be coming out soon. Is this what prompted this appearance today? Well know soon enough.
I expect an attempt to distance himself from the coup.