The github deal with MS closed almost exactly three years ago.
I'm guessing there was a massive financial incentive that he just fulfilled by staying three years. Not a hubber, but this is a pretty common thing to see with acquisitions.
But he was a MS employee pre-acquisition, right? Is it common for the acquiring company to give their employees that manage the acquisition massive incentives that vest in a short-medium window? (Honest question. It's not been common in my experience, but that's pretty limited.)
He was already an MS employee 3 years ago though (he came over when Xamarin was acquired in 2016), whereas I usually associate those terms started when you join the parent company. Granted, 2016 is not that much longer ago, and it does seem plausible there was some bonus that vested after 3 years at Github, so you could be right.
