Dr. Az-Zalmi, in his book التبيان لرفع غموض النسخ في القرآن, pages 220-222, refutes this case on the basis of no contradiction. He says the condition in 4:64 is
quitting hypocrisy while the condition in 9:80 is
insistence on hypocrisy.
He then quotes Ar-Raazi who asked himself the question: Why was it necessary, in 4:64, that the hypocrites seek the Prophet's forgiveness, not just God's? He answers his own question saying that the circumstance of revelation was, as mentioned in 4:60, that the hypocrites refused to make the Prophet their arbiter and sought arbitration in Taaghoot. So, they had to apologize to the Prophet and seek his forgiveness too.
Here is verse 4:60 for reference,