I'm from the generation where things like novels, comic books, FASA roleplaying games, Star Fleet Battles, the Franz Joseph tech manual, and other miscellaneous books, games, publications, etc. were all considered 'canon' between TOS/the TOS films and the TNG era of the '80's, simply because there was nothing else going on in that intervening time.
I never heard anyone use the word "canon" in those days. There was no perception that a story needed a specific label applied to it to define it as valid, or that we needed anyone's official authorization before we were permitted to read or enjoy a story, or that there was some objectively "correct" version of the universe that we had to conform to. There were just stories, and we made our own individual choices about which ones we wanted to "count."
After all, there's no reason to use the word "canon" at all if you assume everything counts. The only purpose for the word is to define what counts in opposition to what doesn't. It's like how nobody called the Great War "World War One" until there was a "World War Two" to differentiate it from.
And there was also nobody in charge telling people that it wasn't 'canon.'
There never really has been. Roddenberry and Arnold asserted that authority in the '89 memo, but they had no actual power to make it stick, beyond telling the tie-ins they couldn't reference TAS.
After all, the original work being the canon and tie-ins not being the canon is the default. That's just what the words intrinsically mean, so nobody has to declare it. The only times it's even an issue are those rare exceptions (admittedly less rare these days) where the tie-ins are regarded as canonical (usually because they're from the original creators and the main series is no longer in production to contradict them). The rest of the time, it should go without saying.
But the unfortunate truth is that as of now, and for some time, CBS/Paramount calls the shots as to what's canon or not. But that doesn't mean that you can't buy a novel or a comic and appreciate it for what it is (or not appreciate it if it's a piece of crap.)
Again: "Canon" is not a seal of approval. It's not an official label. It's just a descriptive shorthand for the original body of work as distinct from its imitations by outside creators. So nobody has to "call the shots." The stuff from CBS/Paramount is the canon for the same reason that the Sherlock Holmes stories and novels by Arthur Conan Doyle are the canon: because it's the original set of works and that's simply what the word means.
And it's not "unfortunate," because canon is not a value judgment. It is all equally make-believe. As long as you enjoy a story, it doesn't matter if it fits with other stories. It's just different, and different is not wrong.