Have CBS outright said it cannot continue?
Considering they’re not canon I don’t get the fuss. This isn’t like Disney with their canon Star Wars books. At least they have a legitimate reason
That's not the point. The reason tie-in literature exists is to support the franchise it's adapted from. "Canon" doesn't matter. It never does. What matters is that these books are merchandising for the shows and films. They exist to promote them, to reinforce them, not to compete against them or repudiate them.
The existing audience for the books is a few thousand people, out of the millions who will watch the shows and films. The hope is that some few of those millions of TV/movie viewers will be curious about the tie-in novels, buy them, and put a bit more money in CBS's coffers. And it wouldn't be good for those new readers to find that the books completely contradict what they saw on the shows. That would just confuse them and drive them away, and CBS wouldn't make any more money from them that way.
More fundamentally, you're trying to paint the tie-ins as a rival for the shows, suggesting that we dismiss the shows as something inferior, "just a nightmare." That would be, frankly, pretty damn obnoxious and ungrateful. Like I said, we don't own these characters and concepts. We have no right to claim them as our own and denigrate the choices of their rightful owners the way you're suggesting. We're just borrowing Star Trek from CBS. If any version of the universe is "just a dream," it's ours, not theirs.