We can hope that conversions are sincere. Certainly the Spirit moves where it wills.
However, remember Spain. There were insincere conversions there by Muslims, who then proceeded to undermine the culture with Islam.
A muslim who converts to Christianity is typically killed. Its a death sentence. There is no earthly advantage to becoming a Christian in a muslim country. Your family will turn on you and to preserve the family's honor they will be the ones who take you out into the desert to dump your body.