If a new yorker retains his new york employer he will still get taxed by new york. Moving to another state would just add to the tax bill (though there is some credit paid to another state). NY is one of 5 states that tax out of state telecommuters. This might keep them from moving out of state for a while.
Depends on whether the company retains a NY office. If you have nobody in your NY office because they’re telecommuting, there’s no need to have an NY office. You just move any support functions to NJ or CT and you’re good to go.
Employee becomes contractor