Might be of interest:
The common belief that the Qur’an has a single, unambiguous reading is due in part to the bravado of translators, who rarely express doubt about their choices. Yet it is above all due to the terrific success of the standard Egyptian edition of the Qur’an, first published on July 10, 1924 (Dhu l-Hijja 7, 1342) in Cairo, an edition now widely seen as the official text of the Qur’an.2
... Writing in 1938, Otto Pretzl noted with amazement that in his day for the first time a de facto canonical text had emerged.6
Yet the Egyptian project was never intended to be text-critical, at least as this term is commonly understood. The scholars who worked on that project did not seek to reconstruct the ancient form of the Qur’an, but rather to preserve one of the canonical qira’at “readings” (here meant in the specialized sense it has in Islamic tradition), that of Hafs (d. 180/796) ‘an ‘Asim (d. 127/745).
But these qira’at are part of the history of the text, not its starting point, and the idea of a discrete number of different yet equally canonical qira’at did not develop before the fourth/tenth century, when great divisions over the Qur’anic text led Ibn Mujahid (d. 324/936), among others, to sponsor this regulatory concept. Ibn Mujahid argued that there are seven, equally valid qira’at. Others argued for ten, or fourteen. The gradual (yet never complete) acceptance of the argument for seven qira’at (often attributed to Ibn Mujahid’s use of a prophetic hadith that speaks of “seven letters” of the Qur’an)7 was generally accompanied with the caveat that each qira’a has two versions. Effectively, then, fourteen different versions were considered equally authentic, only one of which was Hafs ‘an ‘Asim. Even in this scenario there is no unanimity over the precise shape of the Hafs ‘an ‘Asim qira’a. Four different lines (turuq) of transmission are claimed for it, and discrepancies abound in the various texts claiming to transmit it.
In the early twentieth century, therefore, the shape of the Qur’an would have seemed anything but clear. In fact, the Egyptian government was motivated to begin the project that would lead to the Cairo Qur’an edition due to the variations (or “errors,” as an appendix to the Cairo edition describes them) found in the Qur’anic texts that they had been importing for state schools.8 In response, the government destroyed a large number of such texts by sinking them in the Nile River and issued its own text...
However, the Cairo text is often at odds with manuscript evidence.12 This is perhaps to be expected, given that the Cairo project was not about recovering a text as much as choosing a text. Indeed the very idea of canonical qira’at is based on religious doctrine, not textual criticism. In the paradigm of qira’at, discussion over the shape of the Qur’anic text must take place within the context of the community’s tradition.
The Egyptian Qur’an, then, should not be confused with a critical edition. The Egyptian scholars in no way sought to record the canonical variants to their text, let alone the non-canonical variants to be found in manuscripts.
Gabriel Said Reynolds - The Quran in its historical context