Is the waiting period (iddah) obligatory for a woman whose uterus has been removed, if her husband divorces her or dies? And why?

A woman whose husband has died observes an 'iddah (definition) (waiting period) of four months and ten days, based on the Almighty's saying: (And those of you who die and leave wives behind them, they (the wives) shall wait (as regards their marriage) for four months and ten days). Whereas a divorced woman whose uterus has been removed observes an 'iddah of three months, based on the Almighty's saying: (And for those of your women who have passed the age of monthly courses, for them and for those who have no courses, their 'Iddah (period of waiting) if you have doubts (about their period), is three months). The wisdom behind the 'iddah is not only to ascertain the emptiness of the womb but also includes exalting the sanctity of the marriage contract, providing an opportunity for reconciliation, fulfilling the right of the deceased husband, and safeguarding the rights of both spouses and the child.