XIAOBAITU, please help!!

I told my boss I decided to resign from my job yesterday. However, today, my boss threatened me and emailed to me “you need to look carefully at the consequence if you have not received your green card”. He does not know if or not I receive my green card.
My I140 NIW got approved last year and I am waiting for I485.
I got a new job, which is in the same filed with much higher salary.
Therefore, I decided to take the offer.

My question is that if my boss wrote a letter to USCIS, how could this affect my I-485?
He was one of my five references for I-140 NIW application.

Thank you very much,