That would be true if this were a pension.  

"On Jan. 10, 1996, Congress enacted the Pension Source Tax Act of 1996 (P.L. 104-94). This law specifically stipulates that, "No State may impose an income tax on any retirement income of an individual who is not a resident or domiciliary of such State." While the Source Tax law still allows individual states to define residency on their own terms, it prohibits any state from taxing non-residents for pensions earned within the state. If you earn a pension in Vermont, for instance, then retire to New York, Vermont may not tax your pension income."

https://finance.zacks.com/pay-taxes-pensions-state-retired-state-living-in-8131.html

But it's not.  If Congress had wanted to exempt the $250,000 bonus paid in February to an employee who left the company and the state last June, they could have.  They didn't.