I know it's just half-canon or something like that
The novels are, as far as it is known, third-tier canon as the games themselves and Nomura interviews supersede them.
I've read some of Goldpanner's translations, and the best example I can immediately think of are the KH 2-novels. In there, there are some incidents and statements that are made impossible to be canon as later games and/or interviews outright contradict them.
What makes the novels "more" canon than Amano's manga is that the novel author, Tomoco Kanemaki, is actually part of Nomura's team/staff and gets some background info-input from Nomura himself. What
exactly is background info given by Nomura and what is own interpretation of Kanemaki is hard to discern though if there is no actual instance of a game or an interview confirming or contradicting things in question.
psst..should I feel bad for laughing at Roxy yelling "we're going to the beach!" ? xD it makes me laugh, but I know Roxas was so innocent and inexperienced in Days, what he says is so (simple and clean) pure that it might just sound out of place if one doesn't know the context of his life.
I'd say people who do not know the context cannot be really reprimanded if they find it initially funny or weird. Even to people who
do know the context it can still be amusing depending on how it is delivered. The "Who will I have ice-cream with"-scene can still come over as very wtf-like or amusing simply because of the delivery even if you know the true meaning behind it.
*goes to find list of writing staff for the series*
Edit. Game writing staff specifically.
It's somewhat ironic that the one who is arguably the best writer for story pacing and characterization is the one with the work that has the least connection to actual canon.
Kanemaki also does a good job on giving the characters depth and has some real gems inside the novels like i.e. Aerith and Jiminy Cricket interacting or Sora, Donald and Goofy actually reading and contemplating the Ansem Reports in the KH 1 novel, but she has no talent to write actual engaging battle scenes and sometimes it seems the drama goes a bit overboard.
It's sad that the primary medium of the series, the games, actually have the worst writing...