It's not very clear to me why the author of this article thinks that such a turn to "storytelling" has something to do with e-books or the internet. There's nothing in the electronically-delivered format that mitigates against "sentences" except to the extent that the e-medium abandons text and becomes entirely devoted to visual imagery--in which case it will have merely become a cousin to film and video. Perhaps the implication is that the "digital" environment is creating some new form of narrative partly in language and partly in. . .whatever it is that is supposedly replacing language, but if so no attempt is made to specify what this new form might be, nor why, even if such a beast is rising to be born, this would mean that fiction in sentences won't continue to be written. Frankly, the article as a whole seems just another manifestation of the paranoid projection casting the cybersphere as some kind of phantasm that is becoming increasingly common among erstwhile cultural gatekeepers who feel themselves endangered by it.
He continues on to raise important issues about 'this fixation on story':
However, it does seem to me that fiction writers can be separated into those whose first loyalty is to sentences and those for whom that loyalty is to "story." When the latter look at the history of prose fiction, apparently what they see is a collection of narratives, a practice devoted to the crafting of narrative. Some of these narratives are more "traditional" than others, some emphasize external action while others explore subjective responses to events, but finally the work exists to present readers with a story.This fixation on story has only been reinforced by the dominance of film and television as popular sources of narrative. Rather than taking the expropriation of narrative by these visual arts as an opportunity to discover alternative strategies for creating literary art in prose, strategies that inherently require attention to "sentences," most "literary fiction" continues to compete with film and tv as suppliers of narrative.