He has to think about his employees first, they are counting on him so if he leaves, they lose their livelihoods so he won’t be leaving now..now if those people decide to leave along with him different story, but that will be tough considering those people probably have families in New York, can’t expect them to pick up and leave
It would be 100% moral and ethical to tell his employees that they were free to come with him to the new state and that he would even pay some moving expenses. I am certain that he would give a generous severance pay to those who choose to stay in NY.
The only possible problem might be his kids in schools and waiting until the end of the school year might be right. Waiting 3 years does not seem right to me. It is a half-hearted effort.