I will say it's probably useful to have, esp. nowadays with all the extra universe stuff and all. It's good to know what the owners of the franchise consider canon. But it's more useful to you guys who work on tie ins.
As I've been saying, it's a mistake to think that "canon" is something that has to be judged or decided by the creators. That's getting it backward. "Canon" is a shorthand term that we use to refer to the stories told by the creators. It's not something anyone decides -- it's just a term for what they already are, the stories told by the creators/owners instead of other people. It's tautological to say that the creators decide that the stories they tell are the stories they tell. Most of the time, the actual creators don't have to think about the word "canon" at all, any more than a cat has to think about whether it's a cat. The only time canon becomes an issue is in relation to the stuff beyond canon, the tie-ins and fanfic. Sometimes tie-ins are canonical, though rarely so, and thus there can be uncertainties that need to be clarified about how the tie-ins do or don't fit in with the canon. But whether the canon itself is the canon is a pointless and redundant question.
This is the damage done by the '89 Roddenberry memo. It created the false impression that canon status is something that has to be assigned or removed by the creators. But the only reason Roddenberry and Arnold felt the need to issue that memo is because they didn't have actual control over the franchise anymore and were trying to assert their pathetic need for control by bossing around the fans and tie-in authors. The people who actually make the canon don't have to declare that's what it is. It just is.
To complicate things a bit there are different levels of the franchise. What I mean is we have the canon--I think that's pretty much everything shown on screen that's official by the studio such as the various shows and movies.
Not everything shown onscreen, since every ongoing series contains errors and poor choices that are ignored or retconned away later on. There are episodes or films that have been partly or entirely disregarded by later canon, such as "The Alternative Factor" with its nonsensical portrayal of antimatter (contradicting what "The Naked Time" had previously established), ST V with its 20-minute trip to the center of the galaxy, or "Threshold" with its bizarre version of transwarp. The term "canon" applies to the whole body of work, complete with all its internal contradictions and errors, rather than to discrete pieces of it.
In a way, I'm sort of surprised we are arguing about what is 'canon'. I'm pretty sure what is considered Star Trek canon these days is pretty well defined. It's what's on screen by the studio (CBS or Paramount--I guess soon to be all Paramount once again). As far as I know there's no ambiguity about that.
Reportedly the re-merged corporation that owns the studios is to be called ViacomCBS. I'd say CBS Television Studios itself is likely to keep its current name, since it's a powerhouse in TV while the entity currently using its old name of Paramount Television, founded just 6 years ago as a branch of Paramount Studios, is relatively tiny and less influential. The current Paramount TV might be allowed to coexist with CBSTVS, according to Variety, but it would still be CBS that owns Star Trek.
I think I would just simply call them 'tie-ins'. I think that nicely sums up what novels and comics are. You could probably call them extra-universe works, but that's a bit more wordy.
Yes, exactly. They're tie-ins. No need to invent some other pretentious label.
Take TOS. The show airs, and because of its popularity, expands into novels, comics, games, etc. This material is all building a continuity with what was on the show, filling in all the blanks, creating an expanded universe.
Then the next show comes along, and generally adheres to what was established in the earlier show, but not the books. And new books will be written taking into account both shows, but not necessarily those older books that were written earlier. For the books, there are continual reimaginings with each new on-screen production, while the shows are all building off each other.
Actually continuity within Trek tie-ins is the exception, not the rule. Prior to 2000, the only time there was any degree of shared continuity among Trek novels was in the mid- to late 1980s, and that was only occasional and quite loose, with some books referencing and staying roughly consistent while others took their own conflicting paths. Also, the individual comic book series have tended to maintain continuity within themselves but not with each other or with the novels, except in a small number of cases. And the various computer games and RPGs have all done their own independent things as well.
There has been a fairly consistent continuity unifying the majority of the novels over the past 20 years, but not all of them (TOS novels are still pretty much standalone aside from occasional cross-references at the authors' discretion); and the comics, Star Trek Online, and Star Trek Adventures (as well as the David A. Goodman "nonfiction" books from another publisher) all have their own separate continuities that occasionally borrow individual elements from each other but don't agree in broad strokes.
So there's never really been an "expanded universe" in Trek (like I said, it's always a mistake to think that Star Wars terminology can be grafted onto other franchises). There have been continuities linking some Trek tie-ins to each other, but never a single one that all tie-ins have been expected to follow.