Is it permissible for a man and a woman who committed zina to marry each other after they repented, given the existence of Ibadi fatwas that prohibit this marriage, and a reported athar from the Prophet (ﷺ) forbidding it in a similar case?

The Imams of Ahl al-Sunnah (definition) (Sunni scholars) have agreed on the permissibility of marrying someone who has repented from zina (fornication/adultery). Furthermore, the majority of scholars have affirmed the validity of the marriage even without repentance. They based this on the interpretation by Ibn Abbas of the verse: "The fornicator does not marry except a fornicatress or a polytheistess." He stated that this verse was revealed concerning notorious prostitutes and not every person who commits zina. As for the hadith (definition), "Any man who commits zina with a woman and then marries her, they are always fornicators," it is not marfu' (attributed directly to the Prophet), but rather mawquf (attributed to a Companion) to some Companions like Ibn Mas'ud, Aisha, and Al-Bara'. Their statement can be understood to apply to those who have not repented from zina. This is supported by a narration from Ibn Mas'ud that he saw no harm in marriage after repentance. The important thing is to complete the path of repentance and obedience to Allah.