I'd guess that yes, this is a different universe where Superman has killed Zod...or at least, people believe he has. (After all, if he turns up in the 31st century, the idea that he was killed at all is easy to take with a grain of salt.)
Jan. 29 episode had a Computo reference!
IMDB says that Supergirl is returning on Monday, April 16, reclaiming its slot from Legends of Tomorrow.
Man, the latest episode of Supergirl was really frustrating for a Legion purist. Mon-El has been hiding the fact that he still has feelings for Supergirl from his wife, Imra. J'onn gives him some advice about sharing his feelings, even if they're not necessarily comfortable, and says that it was just a way of life on Mars, because they're telepaths.
Which is just where you would expect Mon-El to say, "Yeah, tell me about it. Imra's a telepath too." But of course, on this show, she's not -- she seems to be telekinetic instead. I roll with all sorts of changes on TV and movie adaptations... I'm on the pretty far into the easy-going end of the fan spectrum, I think. But the cognitive dissonance in this scene between what's been established on the show and what I know from the comics is going to make my head explode.
(And yet, despite all that, I have to check myself: I'm complaining about a storyline involving Supergirl, the Martian Manhunter, Mon-El, and Saturn Girl, on national TV, playing out weekly. Somebody pinch me.)
I hear ya, pal. Every once in a while I think, "you know, they could have written in Shadow Lass instead of Saturn Girl, and it would work just as well or better, an it would be consistent with the comics."
But we've seen Saturn Girl on Smallville, she's one of the founders, TK is an easy special effect ... I can think of lots of reasons why they went with Saturn Girl. (Have they ever actually called her that on the show?)
But then I remember "I'm complaining about a storyline involving Supergirl, the Martian Manhunter, Mon-El, and Saturn Girl, on national TV, playing out weekly."
So, yeah. I'm right there with you.
As to the schedule, I wrote about this on one thread or another that Supergirl is taking a hiatus, and Legends is filling the time slot. Evidently this has something to do with Berlanti not wanting more than four superhero shows on at a time. Maybe. Anyway, Legends will return Monday and finish off its season, ending on March 9. Then Supergirl returns March 16 to finish her season, ending on June 18.
I think the four-at-a-time rule might be Berlanti's, or it might be CW's. But yeah, that seems like it's part of it.
Of course, there's also the fact that exec producer Andrew Kreisberg was fired over sexual misconduct, and Supergirl might need a little time to find its footing during a change in leadership. Although he served in the same position over at Flash, and that's chugging along with only a little break during the Olympic weeks. But maybe he was more involved with the day-to-day of Supergirl, it being a younger show.
Regardless, as with the delays in Metal, it's a small price to pay for getting an abuser out of people's lives.
I would guess that the 4-superheroes-shows limit is The CW's idea. They probably want to keep the superhero fans AND the fans of the rest of their shows as happy as possible.
It could also be a factor that, while the "old school" networks have three hours of prime time to fill seven nights a week, the CW only has two hours of prime time to fill (the 10-11 o'clock spot is left to the local affiliates) five nights a week. That adds up to a lot less available programming spots, no matter what you'd like to fill them with.
The four-superhero-shows-at-a-time limit is from the president of the CW, as I note over here.