You know, as I've been saying since my PnP RPG days, it would be nice if in situations companies like this not only declared something non-canon, but actually instituted a recall and refund on products.
Correcting "errors" in something like this is kind of pointless, and hurts the lore and franchise. It's sort of like how companies like Palladium and WoTC/TSR/Hasbro/whever has D&D have made revisions within differant printings of the same "edition" of a PnP book, or how sometimes there will be differances between printings of a given novel. I remember actually sitting down with differant printings of RIFTs, say the main book or Silver Anniversary copy and finding other pre-Ultimate Edition copies that had differances in them. A major shock in that community came about when the now-ancient "RIFTS Japan" was released and some of the classes were listed as having special abillities referancing mechanics that were not in the game originally. Say if you had an original copy of RIFTs, explaining that some Ninja could make a dodge against ranged weapons with less of a penelty was a "WTF" moment. It was referring to the stupid addition of a -10 to all dodges against ranged attacks without the defender being able to use his dodge bonus (now infamous) that simply wasn't in the game before more recent printings and thus probably like 90% of the people were oblivious to. Not to mention how paticularly dumb this rule was to begin with, even if you understand the reasoning which is an entirely differant cup of beans.
The point is that companies need to take responsibility for the things they do, and crap printed products that do damage to an established property. Just as a toddler toy that represents a choking hazard gets recalled with a sincere apology, the same should happen to bad RPG books, or lore-destroying novels like this one.
To be honest, I'm avoiding "Deception" intenitonally, even if I don't normally read much game tie-in fiction. I would however like a side by side analysis as to whether or not this is a worse affrong to the established universe it claims to represent than the famed Harry Potter fanfiction "My Immortal" (which I did try and read... but it causes almost physical pain, I kid you not). Perhaps an idea for an episode of "No Right Answer"? Perhaps an extra long pod-cast edition featuring readings of both works one after another... the guys from Drinking games could stop by with booze to help kill the pain part way through.