I think you're half there, but in the end I stand by it just being kind of poor writing. It's not so much a development of prose tending towards shorter sentences. Rather, the author is making a stylistic choice that uses longer sentences while _also_ loading the sentences with structural aberrations and external, sometimes opaque, references.

I'd argue that it's always been a good idea to use style judiciously in prose, and balance longer more complex sentence structure with fewer references or other oddities. Or load up unusual structure and abstruse language, but keep things shorter.