Is a divorce valid if a father, unaware of his son's marriage to a specific girl, swore by divorcing his wife if his son married her, given that he swore by three divorces?

If a son marries a woman after his father swore an oath of divorce (talaq) that he would not marry her, then, according to the majority of scholars, the wife is divorced three times with a major irrevocable divorce (baynunah kubra). Sheikh al-Islam Ibn Taymiyyah is of the view that if the intention behind the oath of divorce was to threaten and not to effect a divorce, then it is like an oath by Allah, and if one breaks it, an expiation for an oath (kaffarat yameen) is required, and no divorce takes place. However, if one intended divorce with the utterance of 'three,' then only one divorce occurs. As for the case where the son married before the father's oath, it appears that the father did not break his oath, because an oath pertains to a future matter.