回複：但是 EB 綠卡的本質是基於 future job 的

The immigration law just says you have to have the intent to work for your employer who sponsors your green card application after you get the green card. But No any immigration law says you have to work for this employer after you get the green card. So, how to tell you have this intetn or not? USCIS knows it because you have worked for this employer >> one year, and that is why USCIS approved your green card. This is the point. That is why nobody has trouble after he/she changed job when he/she got the green card.