On the other hand, much of the later TV shows and movies used it for details, timeframes, etc., whether verbatim or loosely, so there's a lot of corroboration, before and after the fact. (They also do a very good job of citing their sources, so you know how they're reaching their conclusions.)
Of course if it later appears on TV then it's a different story. That 'sanctions' it. But there is a lot in the Chronology that was never backed up on TV or film.
The Okudas being members of the production staff at the time does not, in itself, until the screen work references what appears in their Chronology, ie the biog details in "Conundrum" for example, or Voyager's belated confirmation that the original five year mission did indeed end in 2270. Until it had appeared on film, such things were still a matter of conjecture/debate, no matter how many fans may have accepted the Chronology as 'fact'.
We all knew Uhura's first name was off-reference meant to by Nyota, but until 2009 it was not canon.
Film and TV hold the trump card.