What is the correct ruling regarding an heir who apostatizes before taking the Qasamah oath?

Primary text

The soundest opinion, as stated by Abu Bakr, is that the oath is invalid. This is because the apostate's wealth is either considered to have been removed from his ownership or suspended. If ownership is removed, he has no right. If the property is suspended, it is doubtful until his status is clarified, and rulings cannot be established upon doubt, especially concerning the grave matter of killing a Muslim, which requires certainty, not suspicion.