SNW was going to be cancelled at the end of this season, until the showrunner argued for another half-season to wrap things up. Which makes too much sense, since this was in many ways a shorter, breezier version of All Good Things. It even ends with a captain joining a poker game! And focussing on Uhura also works well for a pseudo-finale, since she was our focal character early in season 1 as well.
Which makes me wonder how the next season will feel. It reminds me of the Babylon 5 season 4 finale, which was written to function as the series finale when they thought they wouldn't get renewed. And then the actual season 5 felt a little redundant. Not unwelcome, but kind of like a long addendum to the "main show".
Regardless, an enjoyable episode. Celia Rose Gooding carried it well. They had fun with the time travel mechanics in a way that worked well enough. I think Trek relies too much on fan service, but I have to say the '60s hair tickled me, and I was delighted to see M'Ress. The Black / White Holes didn't feel scary enough by far, but it seems like they weren't exactly the real thing, so maybe that's okay.