But what do Muslims do in a non-Muslim country or for that matter any country where the Islamic law of inheritance is not followed or enforced? The answer is that the probate court there will first check the decedent's will and rule per its instructions unless they are in violation of the laws of the land. Thus, 2:180 was not abrogated because Muslims still need it in such case.
Haani Taahir, in his book تنزيه آي القرآن عن النسخ والنقصان, pages 77-83, refutes this claim and quotes Basheer-ud-Deen Mahmood from his exegesis saying the same thing I said in the above quote. Here I am again, thinking that I came up with a novel angle, only to discover that somebody else beat me to it
Taahir discusses scholars opinions about this claim and points out something interesting: Verse 2:180 could not possibly have been abrogated since God emphasizes it with the phrases كتب عليكم
(Written upon you) and حقا على المتقين
(a right upon the pious) and in the next verse threatens those who will replace
That observation was made by Al-Qaasimi in his exegesis محاسن التأويل, volume 3, pages 413-414. Imaam Muhammad Abduh said likewise. He was quoted by M. Rasheed Ridha in his exegesis تفسير المنار, volume 2, pages 136-141. He wrote that some scholars have allowed a bequest to heirs who inherit but, in the view of the testator, do not inherit enough. For instance, they are poor and without a means of support.
This is indeed a real problem. The Islamic law gives shares of inheritance the way it does because it also mandates financial support upon those who inherit more toward those who inherit less. But people do not always observe that and governments do not always enforce it. The result is that people who inherit less end up with the short end of the stick. Imaam Abduh, therefore, agrees with the scholars of old who allowed bequests to be given to some heirs for reasons such as that.
One of those scholars of old was Ibn Hazm Azh-Zhaahiri, who said that a bequest is allowed for heirs who do not inherit because they are slaves, disbelievers or end up with nothing after applying inheritance rules. I was surprised to read that from Ibn Hazm, especially the part about bequests to non-believers.
Ash-Sha`bi and An-Nakh`i both said that a bequest is recommended but not required. I don't understand how they can say that when the verse starts out with the words "It is written upon you". Taawoos and Ad-Dhahhaak said that it is required for kin who do not normally inherit.
On page 162, Taahir adds, "A will to parents is not always necessary, but sometimes it is." Al-Jabri, in his book لا نسخ في القرآن...لماذا؟, page 73, says that the share given to parents can be too little and that's why, he is convinced, a will to them remains a valid option.
Taahir continues, "This matter has been in debate between scholars regardless of their views on abrogation