Well, the prophecy has come true. Alara is gone. But it does leave the door open for her to return at some point, luckily-- at least they had the good grace not to kill off a major character and to give her a good sendoff. I especially liked how Finn and Lamarr invented a way to keep her aboard, as they would have solved the problem in a regular episode where they character doesn't leave, but Alara's personal story led her in another direction anyway. Too often these hypercompetent characters become stupid just in time for a plot development. I'm glad that didn't happen here and everyone got to stay in character.
Alara's story on her homeworld was slight, but well done, and gave a nice little jab (pun intended) at anti-vaxxers. Orville has been really good at slipping in that good old Star Trek-style messaging even if it's just in the background. And on the domestic side, Alara's father actually learned something-- Robert Picardo was great-- and hopefully her mother and sister followed suit. I especially liked how Mister Katan was able to save Mercer with the encouragement of Alara-- exactly the thing she wanted from him but never got. The home invasion by the crazy anti-vaxxer couple was nicely done, like an old movie, from the guy messing with daddy Katan over the ladle to the dead body of the groundskeeper turning up in the bushes. And it was also kind of amusing to see the battle of the Star Trek doctors.
The farewell scene in the shuttle bay was nice, especially Bortus's awkward attempt at a hug and Isaac's hesitant wave.
Alara's homeworld is surprisingly Earth-like for a planet with super-gravity. The ocean looked way too normal, it seems to me-- I think it should have been a lot flatter. And that soup must have been really hot to boil so merrily in an atmosphere so dense, where the boiling point of water is probably a few hundred degrees higher than it is here.
One little moment that jumped out at me was Gordon's behavior in the shuttle. He mentioned several times how beautiful Xelaya is, and then commented how it reminded him how he's just garbage and his family is just garbage, followed by Mercer giving him an odd look. Foreshadowing for a Gordon-specific episode?