Thanks everyone! The problem here is I did make an "odd" spend... I bought Amex GCs to meet minimum spending for welcome bonus. I do not plan to use this card again for any of these spendings, so hopefully this one does not get me FR.

As long as I got my bonus this time, Amex giving me a FR and shutting me down probably does not matter much, as I heard I will still get time to transfer my points out. I can always come back next year after working full time for a year and give them whatever documents they want.