That’s always been the way Trek has done things, at least pre Discovery. A series of random of episodes maybe sometimes calling back to the ongoing plot, then big canon episodes for the finale and premier of the new series.
Thats probably because they don’t have the rights to use the actors likeness in those books, happens to comics a lot. Actors in the newer shows probably have rights to use their likeness in further material as part of the terms.
I can’t find myself getting any excitement up for the new books like I did for the novelverse stuff. I know some of that was a bit fan-wanky small universe stuff that connected things that didn’t need to be, but I liked how it could blaze its own trail and not have to skip between the new shows as supplementry material.
Great, but this episode actually moved forward lots of character arcs via it’s songs. It was a cleaver way to do it as characters can just belt out their emotions in song under “musical rules” so they could pack the episode.
I don’t know about a show, but a trilogy of films during the Romulan war picking up with the Enterprise cast a few years down the line wouldn’t go amiss. They can even canonise Trips fake death.