It does revert in case of divorce. After all, once divorce is finalized, there is no more marriage! But there are cases where one spouse has hostile intent towards another even if there is no apparent abandonment. And the whole “cleave together” bit is mere ceremonial boilerplate, conceived, like I said, at a time when parents did not usually last long after their children married. And what stronger union is there than that between parent and child?
Husband and wife.