From what I have seen, it appears Shannon Fill (who played Sito) retired from acting in 1995.
And is apparently now a clinical social worker (or was, I have no idea how up to date that information is). That being said being pulled back into the biz for a one off voice role isn't
that inconceivable. Could be a nice pay day and she doesn't even have to appear on screen, hell she could probably record her bits from home if she wanted.
Man that was all kinds of surprising. Nick Locarno? Never in a million years would I have come up with him as the season's big bad, and Sito Jaxa not only being mentioned but her death being the trigger point for, it seems, 99% of Mariner's issues! As others have said that's one deep cut, but it makes sense-even if it is a little out of the blue- and it ties Lower Decks to Lower Decks

so I approve.
And I'll approve a hell of a lot more if they somehow contrive to bring her back, I've been hoping for thirty years that she didn't actually die

rarely has the death of a guest character bothered me as much as it did her.
Anyway a great episode, with some great core Trek philosophy at its heart. Yet again Carol Freeman proves she's a dang fine captain (and frankly I'm annoyed at myself for doubting her, it should have been obvious what game she was playing)
"He has lots of internal organs" made me laugh out loud.
One niggle. If Locarno is kidnapping crews, putting the lower deckers in charge and then abandoning their commanding officers on the planet, what happens to the rest of the crew?