I would take any letter signed by a number of Gedolim with a grain of salt. Most of these letters were not seen by the Gadol. Someone told him about the letter and asked if he agreed. What he was told might not be what you interpret the letter to be saying. Sometimes they don’t even ask they just attached his signature to the letter.
So we do not know whether the even letter exists. And even if it exists did the Godel even know about it. Even if he knew about it does he agree with it the way you interpreted it. Give him the benefit of the doubt and don’t slander him.