You could simply ignore the linguistic issues and buff the strength of the Arabic-script-using polities. Turkey for instance abandoned Arabic script for the Latin alphabet in part to Westernize. If they have no need to Westernize because the West is comparatively not all that and a bag of chips, there's a decent chance they and other countries in the same situaton will not swap scripts. So for this, go for a standard Central Powers win WW1; the Middle East thrives sort of timeline.
From a more linguistic point of view, Arabic script has obvious advantages and disadvantages. Crucially all the Semitic languages use consonants as, essentially, the only things that "matter" between word forms (if someone is properly fluent in a Semitic language feel free to jump in here). So they can safely do away with written vowels, economize word space and maintain meaning. In a bunch of other languages this is a problem. As an example in English: run and rain are completely different words but without vowels both words are only "rn." A tonal language like Chinese would be even worse to write in this regard. Now, in Arabic script there is a way to mark vowels, but even this is complicated by Arabic only having 3-ish vowel sounds. Compared to say, Turkish, which has 8-ish vowels, and a heavier emphasis on them, it's not hard to see how Arabic is not quite as conducive to writing the language as other scripts are - like the modified Latin the Turks swapped to. I suspect creating a more modifiable version of Arabic script would be helpful here - maybe as an ancillary part of the movement that created Modern Standard Arabic?
