I think it is true, but I guess we will find out if Tillerson really leaves and Pompeo takes his place. The confirmation hearings are position specific and done by the committees that have oversight of that particular position and government organization.
I am pretty sure I remember this issue coming up early on and the were or did make a movement because it did not require a new Senate approval. But hey I am old and just because I remember everything doesn't mean I am always right.