I'm not finding it an enhancement. I find it something nipping around the edges of what is already known. I find it incredibly dull because it represents nothing but a footnote in history.
It is like a Pocket Books novel on TV. All the major toys have to be put back in the box undamaged.
Everyone's mileage may vary.
We've known for years the Klingons and Federation have been mortal enemies. Now we're finding out why. I assume we'll also have the Battle of Axanar (done by the people who actually own it) and other monumental moments from which were alluded to in TOS.
I though it was him throwing an evil spellbook in the Mount Doom... Yeah, that part of the plot totally unraveled at some point...
I like the existential question of "Is a sufficiently advanced alien actually NOT a god?" versus the usual Star Trek reversal of the question, "Is god just a sufficiently advanced alien?" However, I think they sort of fell directly in fantasy versus Space Opera.