Second, I don't think a change in the genetic makeup (which is what the projections point to) would necessarily mean the death of the Western civilization. In fact, the many Western values have already spread beyond the West, leading to miscegenation of cultures. The same would be true for an Europe with a higher number of people with different genetic makeup.

Personally, I'm more worried about the loss of local values in the face of the giant which is the US, which has much more power to disseminate them than any Muslim country.

A change in the genetic makeup of Egypt, Lebanon, and Syria from Christian ethnicities to Arab certainly lead to the death of those cultures. You don't understand that races and cultures are two very intertwined things.