Weirdly, there are many who leaving MSFT in general. Looks like they are doing something wrong.
Eh, I don't think it's any different than the general trend of people moving around. 23 years at a company would indicate that it's been a pretty solid place to work.
I have no insight into the company as you do, but that is the first impression I’d get from the circumstances. People don’t stay at a company for 23 years only to jump ship for the same reasons early-career people jump around.