Dr. M. Saalih Ali Mustafa, in his book النسخ في القرآن الكريم - مفهومه وتاريخه ودعاواه, pages 51-52, presents an argument for and another against this claim with an implication that he favors the latter. His argument for the claim is that 4:11 is the new rule of division that annuls prior rules. His argument against it is that 4:11 does not mention the categories of people 4:8 mentions, thus there is no contradiction between the two.
I respectfully disagree with both his arguments. 4:11 does not say that it annuls anything. It simply sets the rule about dividing the estate between heirs and makes it clear that this rule is a mandate from God. 4:8 does not say that what it calls for is a mandate from God, thus it is a recommendation. Heirs may go for it, thus please God, or may elect not to. They don't have to.
Furthermore, 4:8 clearly says that the division of the estate is already in progress! That implies that some rule of division has been complied with. Anything given to the poor attendants is therefore done after the division is made.
That is why I disagree with his refutation argument. It is not that 4:8 speaks of heir categories that 4:11 does not; it's because 4:8 does not specify heir categories at all.
A candle loses nothing by lighting another candle.