Just being "the messenger" do you have the message, its context, its date and the source?
Go call up CBS, the current people in charge of Star Trek. Ask them what they consider canon if you don't believe the messenger.
I'm pretty sure that such a statement from the creators (e.g. Roddenberry, Justman, Piller) didn't contain a P.S. along the lines "We don't mind that those that come after us revise the integrity of our characters and feature Star Trek in any way they feel necessary."
Well of course they didn't; don't be silly. Because at the time TOS was being produced, none of them had any idea it would have the cultural impact and longevity that it did. They were just producing a TV show that had a high probability of getting cancelled after the first season and just fading away into obscurity. They would have had no grandiose objective for its future like what many an uber-Trek fan believes. And to throw your own medicine back at you, you "can't possibly know" what any of these guys were thinking at the time.
But "revise the integrity and feature Star Trek in any way they feel necessary" is exactly what happened for the next 40+ years. For better and for worse.
We can certainly argue how to deal with popular concepts that have not been refuted by on screen canon. I just don't think they're up for grabs and should be treated with appropriate respect, instead.
And that's where you're confused. You think that if people don't agree with your opinions, they're "disrespecting" Trek and its past, when it isn't anything of the sort. You keep saying that everyone is "disrespecting" Mr. Probert's work by simply having the gall to think that Sternbach's design was the real ship. Please.

They're simply disagreeing with your opinion on the matter based on evidence that they feel overrules your evidence. But you know what? This has nothing to do with the OP, so I'll just drop it.
So then, Mr. Probert's painting of the
docking bay of the Enterprise-D for the Captain's Yacht is fanfic because at the time he had been painting it, he was no longer involved with the show / a member of a Star Trek production?
Was that painting seen in the show? Was it used in any scene? If not, then it's just an artistic representation of something from the Trek universe, just like any other Trek fanfic. Are you now going to argue that this painting is canon? That would be stretching credibility quite a bit.
It's a very nice painting. But it's just a painting. It has no more credibility to Star Trek canon than if I painted it.
The way I see it, because both had become authorized Star Trek spaceship designers, this authenticates their pre- or post-TNG Star Trek related work to some extent. YMMV.
Authenticates it for what? Being canon? See above.
BTW, love your new avatar.
Sternbach didn't write it. He only illustrated it. And it was released in 1980, which suggests that the illustrations were being done in 1979 or so. And Sternbach did do graphic art for TMP, so he was officially involved with Trek. But this doesn't make the SFC official canon. Don't get me wrong, I love the work in there, and I make most of the material part of my personal Star Trek universe. But again, we can't say SFC is canon or in any real way binding.
Thanks for the clarification. And I also love the artwork in that book; I even own a copy.
Franz Josef invented the Saladin well after TMoST. So, the reference in TMoST reference couldn't possibly be a reference to a Saladin. Personally, of all the currently existing designs out there, I would favor the Saladin, but let's not suggest there is any officialness to that.
Interesting. So if one were to speculate that Kirk did in fact command a destroyer, not only do we not have a name (as per your original question), but we don't even have a design
