Would the Pope say that marriage to a Muslim was being unequally yoked to an unbeliever? That it was bringing Christ into fellowship with Belial?
Are there any spiritual reasons for not marrying a Muslim?
The traditional Catholic teaching is don't marry outside the faith, period. I, personally, was at one point mildly rebuked in the confessional for marrying an Episcopalian. I have a very conservative (but 20th century) catechism at home which insists that a person "seriously keeping company" with a non-Catholic must mention it in confession.