A defeated Abbasid Revolution could be helpful. In the wake of a major Abbasid defeat after the movement had gained strength and momentum, the Umayyads would heavily garrison the Iranian provinces with Arabs again, and probably establish new Arab urban centres on the models of Basra and Kufa. This would affect the balance of cultural and military power and create huge pockets of Arabization. Persian culture would be more consistently identified with subversion and heresy and wouldn't find a springboard for regrouping and recovery of prestige in Baghdad or in the Eastern capitals like Bokhara.
The Umayyad Caliphate is not likely to last very much, but the successor states are probably going to be more consistently Arab in character and self-perception.
Persian culture and language would not disappear overnight, but can become much mor marginal here than in OTL. If the subsequent Turkish groups pick the elite Arab culture, they might help it speading in the countryside instead of the already integrated arabo-persian mix they found OTL. They would not find Persian in place as a litrary language, and that would both prevent them to adopt it, and offer them less motive to turn their own Turkish language into one.