Shoemaker seems to be confused about this. He cites positively Déroche who dismissed the accuracy of the reports of what ʿAbd al-Malik did (Shoemaker imagines ʿAbd al-Malik did much more). But Déroche's argument ONLY works with the existence of pre-ʿAbd al-Malik manuscripts.
Déroche's argument: 1. ʿAbd al-Malik introduced consonantal dots. 2. We have pre-ʿAbd al-Malik manuscripts with consonantal dots. 3. Therefore ʿAbd al-Malik can't have introduced these. Obviously you can't use that to dismiss the historicity of reports if you reject step 2.
The fact that we need just ONE pre-ʿAbd al-Malik manuscript really makes the carbon dating argument a lot stronger. We don't just have an isolated manuscript, we have MANY, multiple of which have an extremely high likelihood of being pre-ʿAbd al-Malik
That one of them might be later than expected, or something went wrong. Sure. Possible. But are we seriously to believe *all* of them would be? The odds of this are astronomically low. We've carbondated an obscene amount of manuscripts, all from a single archetype.
But hey, physics was broken irreparably because "Three body problem"-style aliens interfered, and we really can't trust the radiocarbon dating. Does the argument depend on that? Not at all! Déroche himself is quite skeptical of carbondating and still argues for ʿUṯmān.
In his "Qur'an of the Umayyad's" Déroche identifies a palaeographical progression from Hijazi, to styles that he calls "O.I" (and later O.II) and eventually to Kufi proper. Déroche connects very convincingly, independent of radiocarbon dating that the O-styles are early Umayyad.
The O.I and O.II styles that we see in manuscripts are a highly regularized, and very beautiful calligraphic style. They have *clear* links with a notable palaeographic evolution that we can link directly with ʿAbd al-Malik: his dome of the rock inscription and his milestones.
But even on art historical grounds these O.I/O.II manuscripts appear to be clearly Umayyad. They are notable for their very beautiful and intricate floral ornamentation which are direct citations of the mosaic's of the Dome of the Rock (which was built by ʿAbd al-Malik).
If the O.I and O.II manuscripts are quite obviously to be dated close to ʿAbd al-Malik, the obviously the earlier Hijazi manuscripts predate these reforms and must be pre-ʿAbd al-Malik. There are quite a lot of these, and their radiocarbondating agrees with such a progression.
The traditional narrative about the standardization of the text really seem correct. Uthman ordered a standard text, made four master copies and sent them out to four important regions, companion copies were often destroyed. ʿAbd al-Malik ordered the creation of imperial codices.
If you think these kinds topics are cool, and the critical investigation into the history of the Quran and the Bible in a comparative way is worthwhile make sure to check out my friend @DrJavadTHashmi's course together with @BartEhrman. ehrman.thrivecart.com/bibleandquran/
I'm sure they will touch on several of these topics together, and I am interesting to see how Ehrman reacts to it. Incidentally Ehrman was one of Shomaker's teachers and "Creating the Qur'an" was clearly (and by his own admission) inspired from Ehrman's Jesus Before the Gospels.