I would think that this would be one of the easiest positions to replace. Timeliness is important of course. Hundreds of people could effectively lead the cancer initiative. I am very dubious of the unique value of the individual at levels like this. More important to not hire the wrong person, but there are many right people available.
Reading the Politico article, clear that he was toxic AF, unless there is some real meaningful counternarrative that we are not hearing about. I am not seeing a drove of supporters here or a conflicted staff. Seems like many staff supporting the point that he's an ass. This is consistent with his reputation in the public prior to this appointment.
I will say this, whether head of OSTP or chair of a radonc department, past scientific achievements alone are a terrible metric for determining who should get these positions.
Seems to me that most biomedical science is management these days (for the people who are getting recognized). However, there is a huge difference between getting funding and motivating a staff towards fairly singular collective goals and getting the most out of a staff that is working towards diverse endpoints (as is the case for radonc departments and OSTP).