I have a theory. While I’m not sure this is what happened I think it’s a possibility. Suppose that the Dropout letter was written and published before Joe was told about it?
It’s quite obvious he did not write it. So everyone seems to assume that he agreed to drop out and then the letter was written for him. But if the letter was written and put out for he was told then what exactly were his choices at that point?
I think you are on to it. He didn't drop out they engineered it ( fake letter etc. ) and he couldn't tell the American people about the coup because they would have killed him. I am sure of that.