I've spent 20 years working in Hollywood. This is definitely not anything new, but we are in an up-cycle. Ambiguity is hard to tolerate, in life, in general. Ambiguity is also where personal meaning can arise. However in hard times (economically, culturally, politically, existentially... we're currently in all 4), market forces drive things away from ambiguity and toward one-pointedness. This is reflected in the world of trailers even more clearly than in the world of films - the trailers often specifically highlight exactly the kinds of moments this writer is critiquing, as if the purpose of film is to trade in such moments; the underlying conceit is something like "populist memes are a commodity."
This is what is currently driving pop culture; the commodification of the meme. Movies aspire to be memes - the dominant means of expression and the atomic unit of culture in the present moment.
They used to aspire to be themselves (movies, for their own sake). IMO that ended around 2008. The Dark Knight was the end and Iron Man was the beginning of a new Hollywood cycle; defined by the movie's ability to trade in this currency - memes - which stand alone, isolated, traded out of context of an entire narrative.
Further reading for whoever is interested: Society of the Spectacle by Debord (re: the degradation of being into having, having into mere appearing, as a universal and ubiquitous byproduct of the core function of capital which is commodification)... and Man and His Symbols (re: the difference between a symbol, which is universal and carries a wealth of meaning, and a sign, which is contextual/temporary and carries a fixed meaning).