Update: Not only is this not a “threat,” it’s actually a rather polite notice that Bolton’s book contains “classified information… at the TOP SECRET level”:
WH letter to Bolton warning him against publication of his book as it is right now pic.twitter.com/dsICaKQuJe
— Jake Tapper (@jaketapper) January 29, 2020
Note too that this doesn’t come from the White House per se, but the NSC. There might still be a claim on executive privilege coming later, but this isn’t it.