All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
It is forbidden for a non-Muslim to marry a Muslim woman; the evidence for that is the Islamic source texts and scholarly consensus as stated in our previous Fatwa. This ruling is established regardless of any given considerations or circumstances. The two reasons you have mentioned in the question are part of the wisdom behind this ruling, as explained by scholars. They are meant to be a source of reassurance to the believer's heart and to enhance one's faith that this religion is true and revealed by Allaah, The All-Wise, The Acquainted, who is aware of His creation and what is best for them; Allaah, The Exalted, says (what means): {Does He who created not know, while He is The Subtle, The Acquainted?} [Quran 67:14] The intention of those scholars was not to say that in case of the absence of these two reasons, the religious ruling changes accordingly.
In addition, it is quite unlikely for these reasons to be absent in case a non-Muslim man marries a Muslim woman; and even if they are, then this would happen in very rare cases. Religious rulings are not based on what is rare, but rather on what is generally the case.
Allaah Knows best.