Oh, nothing is canon anymore/everything is canon, now (see, it even applies to this sentence). Every X-Men movie picks a different set of previous X-Men movies to use as backstory. The "clean break" post-Disney Star Wars is constantly rifling through the EU for loose bits of lore to incorporate. It's a matter of taste, and the people whose tastes matter in this instance have changed, and I don't see any particular value-judgement or insult in saying it's pretty unlikely that's what's actually happening on Discovery is what was expected to happen when Desperate Hours, or even the entire idea of having Discovery tie-ins focus on backstory and not interstitial stories, was developed.
I know, we all put a lot of wishful thinking into early statements, looking for evidence that the stories we'd been enjoying wouldn't be superseded by ones we might not care for, but even with our rose-colored glasses I think we would've noticed if the secret, real message on the tie-in strategy was "Remember how the Klingons were banished from space at the end of Spock Must Die!, or how Voyager was consistent with Mosaic and Pathways, and then it wasn't? Our goal is to constantly work slightly ahead of the show, to give you that sense of narrative whiplash over and over again." That seems like the kind of vibe a bunch of people who read for fun would pick up on.
Now, I like subtext and being able to make connections and interpret and debate things, so I'm not thrilled when every movie, season, episode, book, comic, spin-off, cartoon, web-exclusive, bonus scene, reference book, or A.V. Club episode recap becomes a de facto remake we should enter into with the assumption that no prior knowledge stands and all bets are off (heck, if I heard the line right, the most recent episode of Discovery also retconned what cancer is. Weird flex, as the kids say), but it's definitely one way to work. Would I have been happier if, rather than aging up Pike to make him and Georgiou Academy buddies so he'd known something was wrong, he'd say something about how dedicated she was to protecting innocents on Sirsa III and that doesn't seem to fit with her joining up with Starfleet's undeniably deniable black ops organization? Sure, since my knowing more (admittedly unnecessary) detail about what he was talking about would lend depth and shading to the moment, rather than "Lawl, binge-drinking nerds who work hard and play harder." I'd also be happier if Saru and Burnham's odd-couple, Spock-and-McCoy-plus-sibling-rivalry dynamic had lasted more than one episode and two books, or, indeed, if they had a dynamic at all at this point, rather than the Discovery crew's flat and consistent mutual-admiration-society thing. Heck, I'd be happier if spies (or formerly-unofficial borderline-criminal cabals that are now inexplicably spies) didn't wear official spy insignia, or carry it with them while they were under cover. It'd also be nice if the episodes weren't plotted like movie trailers, all high points with no connective tissue or structural support. My kingdom for a poker or rec-room scene.
There'd be a lot to be disappointed about in Discovery season two even if it was making more effort to pander to me, specifically.