That's about the same as Inciarte's career OPS against RHP (.749), so—if there is rhyme or reason, and it's not just reactionary whim—I assume they're figuring the offense is, at worst, a wash, even if Inciarte does rebound with the bat, and meanwhile internal evaluations suggest Inciarte's defense has regressed enough that Acuña–Duvall is better than Inciarte–Acuña (about which ... I'd be very skeptical).
As noted above, for his career, Inciarte is actually more of a "bat" against RHP than Duvall (though it's surprisingly closer than I would've expected). So your argument doesn't really hold water unless they have Bowmans that either his offense, defense, or both have cratered.