Seems to be just jealousy. From what I gather the old CEO and CTO liked him and his successes/goals but other junior level executives did not.

When the new CEO was brought on they started to listen to the junior executives. They poison the well by stating things like how what he is doing isn't necessary or slowing down their own goals.

Just humans being humans. As a result he will likely leave in <2 years. I don't doubt that his old org will falter extremely fast.

It seems like well run orgs with less people are highly susceptible to quick change than large useless behemoths. Seems paradoxical, but a common fate at many companies/orgs.