Studios' preference for more limited novelizations, faithful to the source and adding little or nothing, has been an industry-wide trend in recent years. It's not specific to Trek or to Pocket.
I'm going to show my ignorance here, but I just don't see the point. I mean, back in the day before home video, novelizations served a purpose-- it was a way to relive a movie or TV show you couldn't rewatch on demand.
Now that one can get your film or TV episode of choice on a half-dozen different platforms, what purpose does a bare bones novelization which regurgitates the source material scene by scene serve?
For my money, a novelization is only of interest if it adds character insight and possibly extra subplots. I gots the DVDs, Pocket!