Wrongful term/retaliation/harrassment

Is it legal/retaliation/harassment I recently gave my boss a step down from one position to another with a date and was told the regional manager accepted it that he even fought to keep me in the position I asked for. After he told me he could remove the work pip on me if I did. days later he then asked me to reword my letter effective immedately and that he needs a new letter I explained to him i was not comfortable giving him a new letter and he got angry. I called hr and she was not aware I gave a letter and stated they don't normal except a letter that far out. I explained that I declined to write a new one and was affraid of possible retaliation based on this and I explained to my boss that the reasons I had for waiting and why also explained to hr. If I am terminated for this is it retaliation or harassment.