The article is factually correct.
The epub "standard" that allows consumers to buy epub books is owned lock, stock, and barrel by adobe. They control the DRM, the back-end servers, the reader software, and the file creation software. For all intents and purposes, epub is what adobe says it is, not what the nominal spec says.
Just look at the calibre and sigil forums; whenever there is an issue displaying an epub file, who has to adjust? The adobe software? Or the conversion tool?
Since the committee spec, like all committee specs, is loose and has room for interpretation, and there is no serious compliance program with teeth, the dominant interpretation is adobe's. Moving forward, epub is, in effect, adobe-controlled. No two ways about it; even B&N had to go through Adobe to implement their own *proprietary* DRM, which has now been subsumed and is controlled and licensed by adobe.
Absent a certification program that can tell adobe to stick to the letter of the spec, the true test of epub compliance is how it displays on ADE.
That is true control.
And since they are the ones pushing for its adoption as a counter to big bad evil Amazon they are in fact "developing the epub standard".
Nothing to fault the author for, other than not fully documenting his facts.
But the facts, he's got them right.