The fact is "when I applied for green card last year, I had to submit three years of tax documents to USCIS". I used to be mad at the International Education office for those years I filed 1040 NR EZ. However, the day I received a letter from USCIS asking for tax papers, I sighed in relief. I filed for green card while I was still in F1. This may not apply to you. For example, you might be on H1B for four years before you apply for green card. In that case if USCIS asks you only for the last three years of tax return, you will be fine. You calculate the risk by yourself.