“Headquarters” is irrelevant for state employment laws. If an employee is working within the geographic boundaries of state A, then that employee’s employer is an employer in state A and has to follow all the laws of state A. Same for state taxes.
What about workers in other states (NY) working for a CA-based employer?
Presumably they would have to comply with labor laws in the state as they do today.
Unclear. I first learned about this law in an article about employees potentially losing benefits by moving out of state: