It's unusual to say the least when a top assistant leaves a program for a lesser job and lesser pay, and that top assistant has a long-term relationship with his former boss, and no one on either side of that transaction has any comment or explanation why.

And no, this is not just a "business" like some corporate entity where people are "disappeared" from their jobs and the drones are never told why. If an assistant VP at Microsoft is suddenly dismissed from their job, no one outside the immediate org knows or cares. "Businesses" don't have fans or alumni who voluntarily contribute time, money, and an emotional connection to the success of that organization.