Rev. 17:18 says, "And the woman which thou sawest is that great city, which reigneth over the kings of the earth." She is the city of Mystery Babylon, the Great Harlot that the 10 kings are going to eat her flesh and burn her (Rev. 17:16-17). 

According to Rev. 18:1-3, an angel comes down from heaven and announces that Babylon, the Great is fallen.

Then Rev. 18:4 states, "And I heard another voice from heaven, saying, Come out of her, my people, that ye be not partakers of her sins, and that ye receive not of her plagues." 

There are no Christians ("my people") in the Islamic religion if turns out to be the Mystery Babylon religion so it's not likely that Mecca wouldn't be the city & home of the Mystery Babylon religion.However, there are Christians in the Catholic religion around the world and in the Vatican City which once was a part of the city of Rome. Once wayward Christianity (unrepentant Laodicean church who calls themselves Christians) joins itself and becomes part of the One World Religion, there will be no coming out of it once a person has worshipped the image of the beast and taken the Beast's mark in the right hand or in the forehead. So it is more likely that the Vatican City will be the city and home of the Mystery Babylon religion until it is destroyed by the 10 kings.