Not true, a number of top programs contacted him when he was the DC and he turned them down. He only wanted to be HC at UW.
However, these two statements have a lot of truth to them. Leonhard didn't want to HC anywhere other than UW because he didn't want to move his family around. That, to me, says that he wanted the title of HC but not the responsibilities of being a HC that would involve not spending a lot of time with your family.
Leonhard was PC's right-hand man and Leonhard had a big part in the downfall in recruiting. #1 responsibility falls under PC - and I remember a story that a 4-star LB was visiting for a game and nobody talked to him. Leonhard is the DC, he has some responsibility for that.
One of the reasons that Mac wasn't sold on Leonhard is that when he interviewed him, Leonhard talked about how he would keep a lot of things the same. Mac knew that keeping things the same was going to be a disaster. Fickell always was Mac's #1, but Leonhard did nothing in the interview process to sway Mac into pivoting to Leonhard when Fickell was waffling about taking the position.
Just look at the 2022 game against Ohio State. That was before PC got fired. Leonhard's defense gave up 21 in the first quarter, 31 at half, and 45 through three quarters. Not any different than their performance against Alabama today.