I was mostly being serious. An overly-complicated writing system could ensure some degree of exclusivity to literacy, and it would increase the status of a scribe class that can decipher the writing system.Interesting. I am not sure if you are serious, but this may be the case at least to some degree. Though this is not my main area of skill, it would seem approximate to assume that the addition of vast amounts of kanji like additions to a language's native grammar, would require a specialized class apart from even the traditionally educated, whose profession was simply the transcription of important information and setting of standards fro grammar. Assuming Akkadian does better in its later stages, this could be emphasized with the combination of Sumerian and Akkadian cuneiform into Aramaic and or other Mid East languages, with a particular scholar priestly class intensifying for a longer period of time. However, the issue I see is, how do we ensure that the prestige of this system is maintained? Power is ultimately the origin of prestige and is the fuel by which it operates; considering this point, what sort of structure could provide the fuel with which to allow Akkadian to be used such? In the case of Kanji in Japanese and or similar structures in Korea, this was due to the continued dominance of China as a centre of population and reincarnating empire, such a feat is more difficult in the Western world.
Another option, is a sort of continual Hellenic Mid East, especially Hellenic Iran and Egypt. Thus, as otl, we see the sort of bilingual Kushanshah and Indo-Greek transcriptions develop into an odd combination of Sanskrit, Greek and Avestan.
Surviving cuneiform is an intriguing idea. If the Mesopotamians are not conquered by the Persians, I see no reason why cuneiform would not survive, as it would intrinsically retain the prestige of the script used at their temples, even as Aramaic and other scripts become more useful for "everyday" inscriptions. The Persians already continued to use cuneiform after the conquest of Babylon.
In a way, though the retreat of the usage to cuneiform to only the most official uses makes it easier to intersperse it with other scripts as long as some power supports using cuneiform. We could have particularly antiquarian kings, like Nabonidus, promulgate cuneiform intentionally.
In late Egypt under Greco-Roman rule, the Egyptian hieroglyphs began to be seen as as magical script where the characters themselves had some degree of divine power. We could see something similar develop for cuneiform as well. We could also look to the Ancient Egyptian cartouche. Maybe nobles want to encode their name in the ancient script as a proto-heraldry that also looks divine. Personal names of rulers, important lords and dignitaries would be written in a cuneiform seal to distinguish them from the rest of the text, and these could also be used for stamps and signatures once papyrus and more versatile materials increase in availability..
It would definitely be too late to switch to Greek at that point, but if we go back to the Viking Age, I could see an earlier conversion of the Norse to Christianity causing the adaptation of Greek alphabet from Constantinople to write Germanic languages. The Norse conquests of England would lead to at least temporary communion with Constantinople, and the adoption of a Greek-based orthography. This might be some kind of quasi-Cyrillic, or a more conservative Greek.Maybe England switches over to the Greek or Cyrillic alphabet, due to anti-Catholic prejudic, in the Tudor, Stuart, or Cromwell era? It wouldn't be as big a shift as going back to the Futhark, and it would go along with the self-image of Protestantism being some sort of a reconstruction of the early church, before it was co-opted by the Roman Empire.