According to our family's professionals, a true hyperlexic doesn't comprehend-- they process text almost compulsively, and have a great sense of symbol-to-sound, but can't tell you what the meaning is. This should distinguish an early (or very early) reader from a hyperlexic.
It is also possible to be a very early, gifted reader (=not hyperlexic) and yet autistic (there's one in my family).
The types given in that blog post seems loose to me, and more motivated by "exonerating" possible autistics from the diagnosis than by state of the art diagnostic practices.
Our family's experience is to beware of people saying "he can't be autistic, he's just gifted," because that statement often masks real and treatable issues.
YMMV,
DeeDee
