More like canon-in-waiting. We must be careful about contradicting its conjectures, because of Mike Okuda's easy access to the canon. On the other hand, Ron Moore says he asked Okuda if 2063 is OK for the date of First Contact, and MO reportedly didn't correct him with the conjectural 2061.
2061 vs. 2063 for Cochrane's flight isn't too big a deal, IMO. There are a couple of things that have shifted a couple of years one way or the other since the Okudachron was published, and that was probably to be expected.
For the most part, the book seems to hold up as published. I don't agree with a couple of things, like the dating for TWoK vs. Space Seed. But there is more that is correct than not in the book, IMO.
Would love to see an updated version that includes ENT and the Trek movies we've seen since the last edition was published.
And to answer the OP: No. In fact the authors say as much in the book itself.