It's important to note that this improvement was not seen when students read popular fiction.
Scientific American report on the study: http://www.scientificamerican.com/article/novel-finding-reading-literary-fiction-improves-empathy/.
An interesting question would be, whether students who do not read at elevated levels would be able to profit from reading literary fiction.
With visually impaired students, we recognize that they will learn less than peers when it comes to, say, art appreciation, because of the nature of their disability. Yet with a developmental or cognitive disability like autism, we think that if students just try harder, they will be able to overcome the wiring in their brains that makes interpreting other people's (or characters') emotions and motivations difficult to understand.
There is an enormous amount of literature that is not literary fiction that could be appropriate for autistic students. Philosophy, history, or political theory may be sophisticated or difficult, but it won't require students to understand what characters feel or why they act. Even classical or medieval literature, before the early modern period where there begins to be a more psychological or introspective approach to individual characters, could be appropriate to some students.
I am worried that I may have to homeschool my autistic child at some point because of inflexible standards like these may be.