After weeks of talks, CBS just announced that Supergirl will be back for a second season. However, the DC show will be moving to CBS's sister network, The CW, where the Girl Of Steel will be a little more closer to Arrow, The Flash and Legends Of Tomorrow.
Since Supergirl was first announced in development at CBS, both fans and industry insiders have questioned whether the major network famous for its crime dramas was the right fit for the show, said CBS Entertainment Chairman Nina Tessler to EW.
From the beginning people questioned whether or not a show like Supergirl belonged on CBS, a network more known for its crime dramas than its superhero shows. It quickly appeared that Supergirl fit way better on The CW.
In addition, Supergirl quickly became extremely expensive for the network - $3 million dollars per episode - while its ratings weren't in keeping with CBS's expectations. A move to The CW was the only way to keep the show alive while lowering its cost.
Are We Heading To A Crisis-Type Event?
Now that the move is acted, how is Supergirl going to interact with the others DC shows? It was definitely established during its crossover with The Flash, that Kara's world was completely apart from the Arrowverse. However now, with all four show being filmed in Vancouver, crossovers between them appears much more feasible than ever before.
In the comics, the Crisis On Infinite Earths events brought all the Earths of the multiverse together, ultimately leading to them all merging into one. I could totally see the TV show heading down this road. There is so much already-established worlds the TV shows could use: The Flash acknowledged the 90's Flash TV show as part of the multiverse and Smallville is already property of The CW. Throw in the old Birds Of Prey show and you got yourself your Crisis.
All of this could down the line lead to Kara's Earth merging with Earth-1 and thus allowing more crossovers, even minors one, between Supergirl and the other shows of the Arrowverse.
This is merely speculation at this point but, The CW will eventually have to find a way to bring Supergirl's world closer to the one of The Flash and Arrow if it want to do more than survive.