In your answer to the question on the possibility of an Islamic anti-Christ you said, “Also, in Ezekiel 44:7-8 we see that one of the first things God will do upon returning to the Temple after the 2nd Coming will be to accuse the Jews of bringing uncircumcised foreigners into His sanctuary and putting them in charge. This can only be a reference to the anti-Christ and the false prophet and confirms they won’t be Jewish.” Won’t that also confirm they won’t be Muslims, as Muslims are also circumcised?
Physical circumcision is traditional in some forms of Islam but is not mandatory for all as it is with Jews. There’s also the fact that God only ordained circumcision as a sign of His covenant with the Jews (Genesis 17:9-11). I don’t believe circumcision by a person of any other religion would suffice. The person would still not be a child of the covenant, and would still not be permitted to officiate in the Temple. In God’s eyes he would still be an uncircumcised foreigner.