Superman and Lois was originally supposed to be part of the Arrowverse
Arrowverse fans were heartbroken when the Superman and Lois season 2 finale confirmed that the show took place on its own earth. Not only was it a very late-in-the-game revelation, but it meant that the versions of the Man of Steel and Lois Lane that Tyler Hoechlin and Elizabeth Tulloch were playing weren’t actually the same versions they played on Supergirl.
Arrowverse naysayers may like to say the show wanted to distance itself from the Arrowverse, but that wasn’t the case at all. Heck, it was even suggested that this was the plan from the beginning of the show since it had such a unique tone. But again, this is not the case.
Yes, the last time we see Arrowverse Superman and Lois Lane, they are discussing how their baby son had evolved into two twin teenagers thanks to the Crisis – which clearly set up the premise of Superman and Lois – but there’s more to it than that. If you go back and watch the first season of Superman and Lois, there are some little Arrowverse nods that don’t make sense now.
The destruction of John Henry Irons’ earth by a red wave was a clear nod to Crisis On Infinite Earths, as was Lois’ reference to Lex Luthor and the multiverse. The biggest indicator of all, though, was John Diggle’s arrival, as he spoke about how he and Oliver Queen fought alongside Superman – another reference to the battles during the Crisis. And that has aged poorly, because now Superman is this earth’s only hero, meaning there is no Green Arrow. So who is Oliver Queen on this Earth?
That’s not even taking into account the fact that Lois was supposed to lift a photograph of her, Clark, and Kara when clearing out her desk at the Daily Planet in the second episode, and the crossover with Batwoman that couldn’t happen because of the pandemic.
Yes, Superman and Lois works well as its own show, but the late-in-the-game decision to retroactively set in on a different earth than the Arrowverse creates some plotholes in the first season.