I just file NIW, then get another job H1b approved, since the company can not wait for me, I have to resign my present job ( at University), but the boss here who wrote recommendation letter for me think the content of the letter is not accurate because I resigned, so they want to letter back,therefore they will write to USCIS office to withdraw this professor's letter. but my attorney has filed NIW, does anybody know what will happen if they really write the to USCIS to withdraw the recommendation letter?