I'm not sure how useful the article's narrowness is. Many of these forms were "launched" by short fiction and not by novels at all - still fewer by literal books. For instance, Leinster's 1945 story "First Contact" predates Childhood's End (1953, I think expanded from a 1950 story). Gibson's 1981 story "Johnny Mnemonic" predates his Neuromancer (1984). Not saying these are necessarily first, either, but certainly predate. And not just that bare predating is sufficient - but these stories made major impacts and contained the major ingredients.
Also, I'm not sure how strictly we need to define the "posthuman" in "posthuman space opera" but Bruce Sterling's Shaper/Mechanist stories (early 80s) and eventual Shaper/Mechanist novel Schismatrix (1985) include most everything you'd need for that, even if "posthuman" wasn't yet a buzzword.
As far as general space opera, Doc Smith's The Skylark of Space (1928) probably did launch the intergalactic space opera subgenre and it actually was novel length (though not yet, at the time, a book).