In addition to at least one outlet overstepping what is publicly known with their superlatives, consider that it has been virtually certain that Pence would testify since November 9, when WSJ published his first book excerpt.
After a Year of Executive Privilege Fights, Mike Pence Just Tweeted It Out - emptywheel
The WSJ has published an excerpt - the parts relating to January 6 - from the Mike Pence book coming out next week.It includes descriptions of the following conversations with the then-President, at least some of which Pence was the only witness:
Lunch on November 16, 2020, at which Trump said, "2024 is so far off."